For context, I am playing this mod with ATOM. This means that I have the Space Exploration beacons and modules. But, if my math is right, this is probably a problem which would occur in Space Age, with quality, provided you have some way to burn hydrogen (not sure what this mod adds, as I am running it as part of a super-modpack and never played it standalone).

In short - allowing efficiency modules and beacons containing them to affect this building allows for well over unity power production in the form of hydrogen. Also, even if there is no way to burn the hydrogen with vanilla +DLC + 248k, it seems to make hydrogen basically free. In ATOM, I can break the fluid system so that I cannot output and input fluids as fast as needed, while running off one fission plant. This may be slightly less extreme with less aggressive mods installed, but I think it is probably still abusable and worth addressing.

So an infinite energy exploit. How would you suggest for me to fixing/balancing it? Because I know about ATOM but not how is the mod implemented and the other mods that have but that's it, I don't know more

Well the response there was essentially 'take it to you'. That the entity and all relevant stats are straight from this mod.

The considered response was 'power is basically free from nothing in ATOM anyway'. Which is fair, if slightly inaccurate. Ie. there will be no changes to ATOM and it isn't considered game breaking.

It's not your job to support other mods so if you want to do nothing then that's cool, but I think I could still exploit this with only this mod and the vanilla DLC, and any mod which allows for burning hydrogen for heat or power, hence it is kind of an issue inherent to this mod.

My suggestion is no efficiency modules ever allowed in the thermochemical separator. It already blocks prod modules, or does in ATOM anyway, so this should be easy to code? If there is a code based way to block them from being effected by efficiency from beacons then do that too. Speed modules have a benefit and a drawback, they seem balanced enough to me - they will decrease efficiency, but sometimes you only care about throughput so you may want to use them, as I did, until I realised I can have my cake and eat it too.

Other than that, the only other options I see are remove the module slots, or change nothing and let it be as it is.

I don’t really want to change the mod’s mechanics. I see my role as keeping it updated and fixing things that are genuinely broken, like bugs that prevent people from playing or make something behave incorrectly.

In this case, I see it more as a balance issue than a bug, so I don’t feel comfortable changing the module restrictions or removing the module slots. I’m going to leave it as it is.

Also, to be honest, I’m too lazy to fix it.

Also, to be honest, I’m too lazy to fix it.

Can't argue with that logic.

I'm just providing feedback when I see something which looks buggy or broken. Whether anyone wants to make changes is up to them :)