I can see good ideas brewing, but I don't know if any of it is possible just in the available YAML, or if engine code will have to be added.
Instant surrender of everyone would be a bit too much, but giving the enemy the capability to flee the scene, and so removing any possible points based on kill/capture, or picking up any of their inventory, could be a good compromise. It is possible to have it based on commendations, but again I don't know if the current state of OXCE+ can handle it, or if additional code i necessary. More directly though whether they flee should tie in with morale itself, with low morale over several turns increasing the probability.
I can say for sure that the ability to flee is not available at all right now, and will require new engine code. Maybe we could see it start happening early next year.