if the arp is already swinging, it's not going to reflect that in the dialog

I do not claim to have studied all 7881 Motif XF Arps but if you can point just one of them out that "is already swinging" and/or one that does not reflect it in the Arp Play FX, I'll look into it for you. I think you are assuming facts not in evidence (as they say).

The arps that have swing and timing offsets, those used in Performances, can be seen by looking at the Play FX... They always show exactly what the programmer did to make the phrase swing. I have never encountered an arp "already swinging".

In the Motif XF: call up and listen to USER 2: (C12) Clavi Jam
It uses Drum Arp # 5781 in Arp1
There is 16th note swing being applied
You can see it by
Press [EDIT]
Select Part [1]
Press [F3] ARP OTHER
You'll see the 16th note Quantize and the Swing +25
This offsets the even numbered sixteenth note by delaying them 25 clock ticks.

So instead of the 16th notes falling on:

1-000
1-120
1-240
1-360
2-000
2-120
2-240
2-360

The even number sixteen this are offset

1-000
1-145
1-240
1-385
2-000
2-145
2-240
2-385

If you just call up a Drum kit and apply Arp #5781 it is as straight as can be.

thanks a ton, phil. i thought this dialog

would show the default settings of each arp, regardless of their original programmings. i´m glad that i´m wrong. you helped me a lot. two quick questions if i may.
#1: can you give me the xf/montage arp swing equivalent of "mpc swing rate 55" in protools or ableton live?
#2: is it possible to copy measures inside a track of montage´s recorder?
best

#1: can you give me the xf/montage arp swing equivalent of "mpc swing rate 55" in protools or ableton live?

I don't own any of those. If you give me details I have a calculator and a pencil and will figure it out for you. Really, swing is (or should be done by ear) not by a number value like "55". But if you like to calculate your musical feel, I still say, use your ears... Swing is real time adjustable on the XF/Montage.

I would imagine that since music and mathematics use consistent numbers, the value "55" (my best guess) is a percentage dividing the music time value into 55% against 45%. So if you are dividing a quarter note into two eighth notes (and this would be the same anywhere on earth) the first one gets 55% of the value and the second one gets 45%. I'm assuming the items you named use % - and that 50/50 is the normal straight time.

Make sense? ... Swing is the experience of falling behind and catching up. If you are marching (walking at tempo) this is the ultimate 'straight' time. If, however, your first step, left foot, used 55% of the cadence, and the second step 45%, that's your swing. You still walk at the same tempo but you now have a distinct movement (we call that a "bop" in the USA) not a musical term, although coincidentally, bebop, the musical genre, does in fact, swing. I guess it could be considered a "limp".

You can work it out from here, but you should still do it by ear... "When it sounds good, it is good..." -D.Ellington
The XF allows you to delay, by clock pulses, the even numbered values. A quarter note = 480 clock pulses. An eighth note is 240 clock pulses... 50/50 would be 120 and 120. 120 clocks is a sixteenth note.

55/45 would be 132/108... So Delaying the even numbered sixteenths by +12 would give that same percentage.

If you are calculating sixteenth note swing, your offsetting the even numbered sixteenth notes - as I showed above.

#2: is it possible to copy measures inside a track of montage´s recorder?

No. The recorder in the Montage is a Direct Performance Recorder designed to document the performer's realtime interaction with the selected Performance. You can export this as a .mid to your favorite DAW.
You also have the option to record your interaction (referencing Montage clock) as an audio wav. You can export this as a .wav to your favorite DAW. Drag n drop it - or simply use its built-in 32 Output USB function.