...with a few tweaks, of course:

• repair packs would need to be inserted directly into each tower (like magazines into Gun turrets)
• towers cannot repair entities that are being damaged
• (optional) remove the upgrades to keep it a weak early game tool that relieves the tedium of running around repairing stuff, but can't keep up later once Big biters show up

I don't think it would be overpowered and (in my humble opinion) the lack of autorepair options before construction bots has always been a very bad decision. And it's not like having repair towers would defeat the purpose of Roboport network around the walls - they are still needed to replace destroyed entities.

Is there even a downside to this awesome mod? I cannot imagine playing the game without it.