Short answer: You can simply tell Scene 1 to recall Arp Select 5
From the HOME screen:
Tap “Scene”
At the top of the screen select “Scene 1”
Turn the “Arp MEMORY” switch = ON
Tap the word “Arp” to view the current selections
Select “Arp Select” #5
You can activate the “Arp Master” for the Scene

Background and Details What gets “merged” automatically, what does not... and what’s a Scene?
When creating your own custom Performances, as you have done, you can “Merge” (add Parts) programming from other Performances.
By tapping “+” in an empty Part slot you launch the “Performance Merge” search engine.

Blue items are Multi Part Performances, green items are Single Part Performances. These are merged to the existing Parts of your current program. You can search “Bank/Favorite” (where to look), you can set “Attributes” (what kind to look for), you can designate the “Source” (which Part or All Parts of the selected item).

It is important to grasp that your selection will be ‘merged’ with the current data, and all programming comes along... but only the Part settings are immediately applied... those that are considered Common Performance parameters (overall) do not get applied automatically. (This is because each Performance can have only one set of overall parameter settings).

Here’s what that means: your merge candidate is leaving its original HOME and is taking up residence in this new location, it now is going to call this new location, HOME. Therefore any programming on the upper Common/Audio level of the merge candidate is held in a buffer. You must first determine if you have enough resources (controller setups) to accommodate the new members (a Performance can have 16 Control Source/Destination assignments).
And you must now tell the system what Assign Knobs to use — because Part numbers are different. (In its previous HOME what was Part 1 is now in Part 4, so for upper level Knob assignments to make sense you will need to address each one, to avoid conflicts). And you need to determine if the previous programming actually still makes sense.

This prevent conflicts and allows for an orderly workflow. Items that were “shared” in its old HOME must be updated here in the new HOME... on a case by case basis. If this sounds like you need to re-program the entire upper level of the architecture... it is not that problematic... the operating system holds your detailed Control Assignment (the Curve Type, the Polarity setting, the Ratio, the Parameter 1/2 shape control) Destination settings, you just need to attach them to a new Source (Controller) Knob... one that is available in *this* Performance. It is really quite elegant. You just need to activate it.

It is very much like new members joining the band... they don’t bring their own console... everyone shares the same mixing console. Everyone share the same room acoustics, etc. you just need to plug them in... at Home they were using channel 1, now they may use a different mixer channel... same thing.

The Part parameters, (that’s everything concerning the instrument itself: Waveforms, Envelopes, Filters, Insertion Effects, Velocity application, key mapping, associated Arpeggios, associated Motion Sequences, etc., etc., etc.) are all in place and ready to use.

Why you don’t COPY Performance Scenes...
Next to understand is the SCENE. There are two types... the Performance Scene, and the Sequencer (Pattern) Scene.
The Performance Scene is one you use to play (perform). It is a snapshot of a specific set of synth and mix setting parameters. (These happen to include the Arpeggios associated with Part). Arp Select, Motion Sequence Select, Mixer/synth offset Settings, Super Knob Link, KBD CTRL status, Arp/MS Play FX

The Pattern Scene is one that is used to document your performing as MIDI events — here Arpeggios are transferred to MIDI track events; real-time ‘swing quantize’ offsets are printed to the Track as events. Pattern Scenes can utilize loop recording or one shot recording/overdubbing and be from 1 to 256 measures in length. They can be “chained” in a specific playback order and then converted to a linear song. All the settings of the Performance Scene apply and additionally a Length function is added to accommodate the transfer of Arpeggio Phrases to MIDI events.

Scenes Change events can be recorded to the linear MIDI Song function, then imported to the Pattern Scenes (by using “Get Phrase” to capture a region of Measures. Sequencer Scenes that contain MIDI events can be copied.

You are concerned with the “Performance Scene” parameters... Scene “snapshot” memory assembles the current conditions of all the supported parameters. You do not so much COPY a Scene with a routine, you capture the settings, [SHIFT] + [SCENE 1-8], you would take the particular item or items you wish to duplicate or move, and you put them where you would like them... when the current settings are correct for what you’d like to do: Store the Scene. Scenes are immediately editable/storable.

When you merged your Performances the Arpeggio Types assigned to the Parts were automatically placed in your new Performance with the same layout as previous. They Arps have their own ARP SELECT function, independent of the Scenes... any Arp Select 1-8, can be associated with any Scene 1-8. Arp Select 5 does NOT have to be Scene 5. Mix and match at will.

The Arpeggio Types assigned to Arp Select 1-8 are the same as they were before you merged Performances. In other words: all 8 Arp Selects are the same as they were...they all were brought along. They are not yet associated with SCENE buttons, nor does the Arp On/Off Master activate (if the Part was set Arp On, or Arp Hold, that setting is automatic, it’s a Part parameter — the Master Arp switch is not, that’s a Common parameter).

Options:
You can use the COPY/EXCHANGE function to swap the Arps associated with a Part from Arp Select 5 to Arp Select 1
When you are on an Arpeggio screen [SHIFT] + [ EDIT] brings up Arpeggio COPY/EXCHANGE (green is active).
Or
You can simply tell Scene 1 to recall Arp Select #5

Hint: all your Scenes can recall Arp Select 5 — if you only activate the Arp Memory Switch in Scene 1, then that assignment will remain active throughout all Scenes unless it is told to do something else — useful when all you want to change is the lead instrument, or the mix balance, or switch to a triplet feel

Thanks for the question. While the actual answer is short, the background material will help fill in the info behind what items are brought along, which are not, and why. A Scene is made up of various settings, which in most cases can be copied separately, individually. Understanding how the system deals with Common parameters, versus what it does with Part parameters and offsets associated with a Part... is important to custom Performance creation.

Hope it helps.

If Scene 5 really is doing what you want without further editing and scene 1 is doing what you want without further editing - but you just want to swap the button locations then you could use the fact that saving scenes and recalling scenes is fast and simple.

Generally:

0) Press [PERFORMANCE] (HOME) to start - general housekeeping step
1) Recall the scene you want exchange by pressing its scene button (pick one of the two scenes involved in the exchange)
2) Hold [SHIFT] + the scene button for an empty scene (any scene that has the scene button LED as OFF) This temporarily saves a copy during the exchange
3) Recall the scene of the position you want to exchange. The 2nd scene you didn't pick in the first step. Do this by pressing its scene button
4) Hold [SHIFT] + scene button of the scene number you selected in step 1. This will copy/overwrite and is half of the exchange
5) Recall the temporary scene location you created in step 2 (it has a backup copy of the first scene involved in this)
6) Hold [SHIFT] + scene button of the 2nd scene position in step 3 to overwrite it - completing the exchange.
7) Optional: Now you have one extra scene - the temporary location created in step 2. You can delete that scene to clean up behind yourself.

If you were swapping scene buttons 1 and 5 and scene 6 was empty/unassigned there are two ways to do this, but I'll start with scene 1:

0) Press [PERFORMANCE] (HOME)
1) Press Scene 1 button
2) Hold [SHIFT] and press Scene 6 button
3) Press Scene 5 button
4) Hold [SHIFT] and press Scene 1 button
5) Press Scene 6 button
6) Hold [SHIFT] and press Scene 5 button
7) Optional: On left-hand side of touchscreen press the "Scene" menu button. On the top row, select the "Scene 6" folder. Then the next row, turn OFF every "Memory" button. Then hold [SHIFT] while pressing the Scene 6 button to save the edits. This will cause Scene 6's LED to turn off as no memory locations are turned on.

This ignores if it's easier to just add one item to any given scene button. It's if, given any other option, exchanging the scene buttons is still what you want to do.

Thanks Bad Mister for the background "theory" behind it all - I will study it.

Thanks Jason too !