I'd say: Keep it like it is now: No bots tradeable at all.
Why? It makes fights more balanced as everybody dies.
Fights do not end with "zero losses" on one side any more. And that is good.
Even when fighting a hugely superior group (either numbers or skill), you can focus one or two down whereas the good group would feed their target and feed and feed, making it a "all down vs. no losses" outcome.
Even aces can be neutralized, while you can never to that when they are fed. Draining an ace is near impossible when he gets fed, and you bleed members of your team at the same time without getting anywhere. That would be the reality again if same-class-feeding is allowed again.
Playing very often on the losing side showed that in pure snub fights, the "no trade" is good. Even when confronted with the strongest groups, we managed to take one, sometimes two. And that is a huge difference compared to "no enemy kills, all friendlies dead" , especially from a motivational factor.
I also say keep it as it is now, although I've yet to see the repair ship out at work yet, so that would be an even better addition than going back to bot trading.
After some time with the new system: I like it. It works, makes fights more fast-paced and generally more enjoyable. And that comes from me, who usually ends up on the wrong side of the bluemsg.