This has been true for all previous Motif and Montage and MO Synths.  The edit flag is easy to trip without manually editing parameters.   Still it tells you if you hypothetically stored the Performance you would store something different than what was initially pulled up.  There's features to restore back the pre-edit Performance so that can be used to restore the original.

'Recall' won't do it - what 'restore' feature do you mean? 

My tests show, on the M8X, using 'Recall' abandons the current performance and loads the previous one.

1. load ANY performance - say 'A'

2. load Init Normal (AWM2)

3. make several changes to the init

4. on performance home select the performance name

5. press 'Recall'

6. confirm you want to do the recall

7. performance 'A' is reloaded

Does it work that same way on classic Montage?

Recall buffer contains last 'changed' perf as long as power is ON. When you load a performance the current performance overwrites the recall buffer IF, and only if the current performance has been changed.

My tests show that if you load a new performance and the current performance has been changed (even just the edit flag) that current performance overwrites the 'recall' buffer. It does that even if you didn't actually 'STORE' the current performance before loading the new one.

1. Power ON - recall buffer is empty - edit buffer has CFX + FM EP by default

2. make a change to the current perf but don't save it

3. load perf A - that will copy CFX + FM EP to the recall buffer

4. make a change to perf A but don't save it - CFX + FM EP is in the recall buffer and perf A is in the edit buffer

5. load perf B - since perf A was changed it will overwrite perf CFX + FM EP in the recall buffer before loading perf B to the edit buffer 

So everytime you load a new performance the current performance, if it has changed at all, gets copied/moved to the recall buffer. If the current performance hasn't changed the recall buffer will have the previous performance.

The RECALL never does a 'reset' of the current performance since the current performance doesn't get copied/moved to the recall buffer unless you load a new performance.

You can't load a perf, make changes and then use RECALL to get back to the original perf.

Even if you store the changes first the perf will only get to the recall buffer if you load a new perf.

So I'm not clear on how you can 'undo' changes you make to a performance except by actually reloading the performance from user storage.

There's the [EDIT] button which (temporarily) restores the original pre-edit settings.  Permanently there's the [INC] [DEC] dance to go to the next/previous (original) Performance.  Or the longer route of going to category search to freshly "load" the same Performance and then you'll be able to use recall if you really do want to get back the edits that were made before.

I do agree that it's really easy to alter a Performance since knob positions are a portion of what's saved and its easy to bump these.  It would be a "neat" feature to have a way to restore just the knob positions and any other settings that do not require pulling up a menu (button states, for example) that would place those back to the last Performance saved values and leave all of the menu-diving parameter changes alone.  At some point you can poke holes into any system and I think Yamaha's general philosophy is not to provide life preservers for features which could be helpful in some instances.

Since most of the knobs that are easy to knock off center are also stored in scenes, I use scenes to put everything back to original values.  Superknob position memory is turned on for my "home base" scene and pressing this will put all of the assignable knobs in place since I rarely de-link these.   This approach doesn't cover everything (and de-linking assignable knobs would have an impact on coverage too) but it's a good portion of what's needed to manage.   Then before I [STORE] I'm sure to press the home base scene number to ensure as many settings as I could cover with the scene are initialized to my preferred values.

Edit (Compare) doesn't really 'restore' anything.

There's the [EDIT] button which (temporarily) restores the original pre-edit settings.

My intention is not to be 'aggressive' but to be as precise as possible so people can understand what is really going on.

If you are editing then pressing EDIT will display, not restore, the settings in the compare buffer which are the 'original pre-edit settings. If you edit, make changes, and use STORE the current edits are both stored AND copied to the compare buffer. Subsequent 'edit, change, compare' operations will only bring back the last stored version.

At least on the M8X the user has no way to actually 'restore' the contents of the compare buffer. The STORE button is disabled in compare mode. 

My comments about the Recall buffer were to try to address the misconception that the 'Recall' button can be used to restore the current performance to a previous state before changes were made. That isn't possible.

P.15 of the M Operation doc describes the recall buffer:

The Recall buffer is used as a backup for the Edit buffer.
If you accidentally changed to a different Performance without first storing the setting, you can
use the Recall function to restore the temporarily saved settings from the Recall buffer to the
Edit buffer.

The recall buffer isn't about the current performance but only the immediate prior performance.

and the compare buffer:

The Compare buffer is the area for keeping settings before making edits. By using the Compare
function, you can bring the settings temporarily saved in the Compare buffer to compare the
edited and unedited sounds.

Curiously, although you can bounce around the menus and SEE the 'before edit' settings you can't actually do a 'restore' to keep them. I think that may be where some people think they can use RECALL to do that - but you can't.

I do agree that it's really easy to alter a Performance since knob positions are a portion of what's saved and its easy to bump these.  It would be a "neat" feature to have a way to restore just the knob positions and any other settings that do not require pulling up a menu (button states, for example) that would place those back to the last Performance saved values and leave all of the menu-diving parameter changes alone.  At some point you can poke holes into any system and I think Yamaha's general philosophy is not to provide life preservers for features which could be helpful in some instances.

People have ask for that sort of 'freeze' thing before but I can see where that would be really messy to come up with a set of specs that could be agreed upon. Perhaps the age-old advice of 'save often' is the best after all. Leave it to the user, when designing, to work on one area at a time and save multiple versions of their work if they want.

Since most of the knobs that are easy to knock off center are also stored in scenes, I use scenes to put everything back to original values.  Superknob position memory is turned on for my "home base" scene and pressing this will put all of the assignable knobs in place since I rarely de-link these.   This approach doesn't cover everything (and de-linking assignable knobs would have an impact on coverage too) but it's a good portion of what's needed to manage.

That's a good approach. I make sure that if I use even one scene I program ALL of them. That way I don't have to worry about one of them doing something unexpected.

   Then before I [STORE] I'm sure to press the home base scene number to ensure as many settings as I could cover with the scene are initialized to my preferred values

Another good one - and always manually restore physical controllers (sliders, pedals, master volume, etc) to a known position.