Antenas could increase psychic sensitivity but worsen hearing (assuming that having antennae = no ears). Insect antenas are for feeling things and smelling the air, but they're actually deaf in the normal sense (they feel vibrations through the ground with special feelers in their feet... Toph Beifong is the true insect queen lmao).
Mandibles among insects are super varied in their design but are generally for fighting, eating or both. Melee combat and eating speed (what a welcome addition those would be since super-gene pawns spend so much time eating) could be improved.
Squirt stinger. Some insects can squirt acid and poisons. Functionally either the same as a shoulder-turret or a Rimworld of Magic ability.
Web-making. More an arachnid thing but some insects make webs. Being able to make webs that slow down movement speed. Can be destroyed for web material, which is a fabric like cloth that can be used for clothing and similar things.
Hibernation Stores. This is a little generalist since it could fit into any gene mod but having a larger food bar. Needs to eat twice as much to be full, but then twice as long before they're hungry again.

butterfly wings? instead of increasing movement speed, increase beauty?