Hi and greetings from the Netherlands!
The 3FMT is al very warm sounding box comparing to the Omnia one... to me, it sounds much more musical and much bigger!
Set the compellor's leveller / compressor knob a quarter to nine driving the level to "0" dB... and only activate the "unlink" button... ref levels (on the backside) @ +4dB...
Set the WB AGC drive in the Omnia to +6dB
attack @ 2 or 3
release @ 4 or 5
for starters:
the warm bass on +1dB
the deep bass on +6dB
the phat bass on +2dB
Just play with the gain section toward the Multiband AGC to get a good balance en enough gain reduction to get a consequent sound.
keep the attack time on the MB AGC slow... in the lowband modest gating (4), in mid band the gating @ 2 or 3, in the high band depending on how much gain reduction you'r doing about 3 or 4...
attack / release in the MB AGC for starters:
4 on the low band, 4 ore 5 on the release
3 on the mid band, 1 on release
3 on the high band, 3 or 4 on release
Try to avoid much limiting in midband en highband.
set the threshold level for the limiter in the low band below zero! (-1 ore -2) to keep a consistant signal! you can gain loudness by setting a faster release time on the low band limiter... If you go for a faster release on the limiters, don't forget to set the end mixer newly!!
Remember: less is more

Set the main clipper at max. -0,5dB!!! the main clipper on the 3FMT isn't that good!
The composite clipper however is very useful! set it @ about +2,0dB!
Try keeping the gain in the end mixer between -2dB in the low band en +2dB in the high band...
good luck setting up a great sounding box! ;D
l