There are "robot" versions of the defender, distractor and destroyer. They're crafted using robot flying frame. I'm guessing they're supposed to work similarly to construction and logistic robots. You leave in them in your inventory and they activate in combat, unlike capsules, which expire after certain time.

Am I wrong? If not, how do I activate them? I've tried every personal roboport, but they simply don't activate.

I was going to do more with them than I did.
I did activate them at one point so that you can just place them like you do with Logistic and Construction robots, but the "ghost" one floating on your cursor counts to your robot limit, so it just deletes one of your existing ones if you were already at your limit, as it does when you launch too many, so I removed this feature.
They were going to be able to be launched from Ammo, but the Ammo doesn't have an ownership, so the game crashed on any robot that is supposed to follow you around.
The only ones that did work were defenders, and those are actually used in the Artillery, but I may have made that cost capsules for simplicity, I don't remember.

There was going to be a Robot launching turret that shot them as ammo too, but I didn't get around to doing that either.

But the short answer is, I never actually wrote everything I intended.