0.Porting interface
like I want to use same mechanic but I dont want to just steal your idea,I want there`s a way to register bot into that,and given them a proballity of breaking,
and when break,I think you can just trigger entity.die(),which can have nice little explosion for it.

1.engine unit
Personally I think you can delay when you can get these bot until engine unit,and also blancing combat bot with simillar recipe like
(engine unit+gas+repair pack->Fueled early construction bot)
(engine unit+gas+machine gun+ammo->Fueled defender bot)

2.looting table and refueling
using loot,allow bot have nice chance drop early construction bot and fuel it later.

*when bot died,drop unfueled version 80% of time
(early construction bot+gas->Fueled early construction bot)
(defender bot+gas+ammo->Fueled defender bot)

3.chance of breaking
if these bot has 100% drop every time,then automatic pickup loot will become infinite loop that consume bots.
which can be a research control the breaking rate.

[Repeatable Construction-x: Chance of bearking reduce 50%]//that is 100%(un-researched) ->50%(once)->25%(twice)->12.5%(3 times)... (apporach to 0% as more you research it)

about charging,I think I will let these bot die if they run out of energy,and disable personal roboport charging ability at same time.

Hey, this mod isn't really meant to add that much complexity, it's mostly there as a convenience to avoid the early-game building grind.

That said, the source code is under a permissive open source license, so feel free to take it, and expand on it with your own ideas :).