just my opinion.....I wouldn't set up your LEF / LES with elevator, as you said the real one is computer controlled and their deployment without some type of asymmetry protection ( like the real one has ) could get ugly in a hurry.
Just set them up with flap deployment. A Set movement with flap position. A little bit at half, a little bit more at full flap. Then tweak to taste with flight experience.
Also i think the SU 27 has leading edge Flaps not leading edge slats. A slat would extend away from the wing like an F100 or A4, however I could be mistaken.
A leading edge flap is simply hinged at the top of the wing. But doesn't separate from the wing. Keep up the great work, totally green with envy and looking forward to seeing it in person.