So here's a thought.
We have master fleshcrafters, who work for commission. This is something unique to the DE.
Why not make use of that? Why not give our characters the option of getting enhancements as wargear?
Give the Succubus the option of buying a Synaptic Booster to give her always strikes first, or have her muscles enhanced for +1 Strength.
Have our Archons taking Cerebral Enhancers that allow him to outthink the enemy even better, giving him more command points or the ability to shut down enemy stratagems. Let him have implanted weapons to catch would-be assassins off guard or get that extra dirty edge in a fight.
The possibilities are endless, and potentially a lot of fun. AND they don't require new models or alterations to the kits!