You can to create a User Style with different Variation on SD9, SD90, SD60 but it's only for Audio Drums and User Audio Drums..
This means that we can not create different orchestration for each Audio Drums Variation..
For each Ketron Style we can to create 3 different Chord Variations/Orchestration: Maj, Min, Sev on each Part (Variation, Fills, etc)...
If you want to create a Floder with normal User Audio Drums wav Audio Loop Parts we must give manes:
ARRA.wav = For Variation A
ARRB.wav = For Variation B
ARRC.wav = For Variation C
ARRD.wav = For Variation D
If You want to add an additional Variation Audio Drums elements for arrangements A / B / C / D, these additional files
should be named as: ARRA_1.wav, ARRB_1.wav, etc
Some Preset Audio Styles have been created with this method...

WOW! Thank you Sokratis! It's perfect to create additional drum variations (even for some factory/copied styles!) ...

Never new this..

It shows yet again Ketron styles have most depth... from all brands

This is illustrated in this video we did showing off one of the new American Country styles with walking bass lines (starting at 00:33).

Video:- https://www.youtube.com/watch?v=lAGfNFvsUic&t=365s

Notice top left side of screen showing A-1, C-1, D-1 .. etc. These are the 1st 4 standard variations. At 02:04, variation 8 is activated by simply pressign Arr D once more to go from Var D_1 (Variation 4) to D_2 (Variation 8).

So ...

Variation : Screen displays ...
Var 1 = A_1
Var 2 = B_1
Var 3 = C_1
Var 4 = D_1
Var 5 = A_2 (accessed by pressing Var A twice).
Var 6 = B_2 (accessed by pressing Var B twice).
Var 7 = C_2 (accessed by pressing Var C twice).
Var 8 = D_2 (accessed by pressing Var D twice).

Hope that explains.

Thanks,