Ok, just guessing and I don't usually do 4 servos for ailerons, so I thought I'd try it out.
So, I set the Aerotemplate to 2 ailerons and 2 flaps. Set both aileron servos to 150% epa's and left the flaps as is. Set 2 C-mixes. LA+ to LF and RA+ to RF, both with points 1 & 9 set to +/-150%. Set FL1 and FL2 switches to null and both C-Mixes to On.
Works, all 4 channels go to +/- 150% at full aileron deflections and the trims work too. Did not try D/R's so I don't know that answer and I didn't try Flaperons.
So, I'd guess we need more details.
Update, I looked closer and indeed the flaps aren't in sync with the ailerons.
Ok, I see what's going on. If you look at the graph on the C-mix. With 150% epa's on the master channel, the master stick input (ail) to the C-mixstops at 100% epa, giving the 150% output on the slave (as set or whatever is set), but still leaves the ail stick well short of the stop - the portion between 100% epa and 150% epa. Effectively, any master channel epa over 100% will not cause a response on the slave channel, the slave channel will have maxed out at that point. As the graphic is drawn, you get +/- 100% on the master against +/- 150% on the slave. But, at anything less than or = 100% epa on the master and the C-mix has balanced output.
So, I'm not a glider guy either, but I tried it there. Set Glider template to 2 ail and 2 flaps. Disconnect stick from flaps in VR menu and assign stick to MTor motor. Set aileron to +/-150% epa's and set flap epa's to +/- 0%. In Mixing,go toAI to Fl1 and set 100%for LA>LFand RA>RF. In Sw menu set AI to FL1 to On. This seems to work perfect.