could you make robots use gates, like trains do, when the player is not near the gate?

I cannot do that, it's a factorio pathfinding AI issue. I highly doubt the devs will make it happen. My droids use biter AI and the devs have no reason to allow biter path finding to consider gates on their team as pathable.

Please heed my various hints on the wiki where I say do not deploy droids inside walled areas. Always have gaps for them to get out or deploy on the outside or on the edge of the factory walls.

yeah, already thought about that. really wouldn't make sense for biters to open doors, esp. in MP-sessions (pvp).
thanks for the answer