Sad to say I'm having an issue with this mod right now. I'm getting a bad movement stutter with the player character, bots, trains anything that moves in the base game with only this mod installed. It was happening in my previous version of the base game and I just upgraded to 1.1.48 hoping it would fix the issue, sadly it did not. I deactivated all my other mods one by one trying to narrow down the culprit. I really love this mod and I hope I can find a fix for it. Thanks for any help.

OK, that does sound like a problem - although this mod does do a lot of performance heavy things anyway - they might still be happening.
Does the stutter occur in a new map, or only a map you have previously used (and if only in a previously used map, have there been any nuclear detonations particularly any with >=100kt yield - and how recent were these nukes)?
Do you have any other mods which might interact with True Nukes (e.g. Realistic Fusion Weaponary), as these might have broken True Nukes's internal state (unlikely, but possible)?
What do you get from the debug info - hit f5 to get this (I'm interested in the script update time and the fps)?

I'll have to try on a new game but it started stuttering on my main game save. At first it was just a slight hitch every few seconds I could live with, but now it's gotten worse and makes the game all but unplayable. Yes I did one large bomb (the 5 tritium canister one) I believe that was 100kt) I've done many 1k, 500t and 20t artillery shells as well. Untold many of the nuclear machine gun rounds as well. I do not have RFW installed, it was too realistic for my likes, I just wanna kill bugs LOL. I'll get back with the F5 info next time I play (probably tonight)

For a new game with all mods on, no lag or stutter. I tried pulling all the mods out a few at a time and loading a copy of my main saved game (900+ hours) and could not find a direct conflict with any of the other mods. Saving a copy of the game with all mods off and all entities removed upon startup the game runs fine 59-60fps. So there is a conflict between loaded entities and True Nukes somewhere but it would take forever to narrow it down. With True Nukes deactivated I can run my main game save just fine at 60fps. Add TN back in the mix and I get initially 20fps and it slowly ramps up to topping out around 48fps but with the stuttering movement. I hope this makes sense to you, I'd love to keep your mod in the game.

Have you detonated any major nukes in the game?
It is possible that the lag is caused by the water movement simulation, which runs for a while after the nuke detonates. This will take a while for larger nukes (100kt or more), so if that nuke was in the 'recent past' - like last hour maybe - then that might explain it. Other than that, I'm running short of ideas. Maybe I'm not clearing a table properly and it has slowly accumulated entries. Alternatively, the game is generating huge numbers of new chunks, and my chunk generation script is causing problems, although I doubt this as that would make your map use huge amounts of space.
TBH, I might need your savefile to get a better idea of the problem.

I would currently guess that the problem is something True Nukes does on its own, with relatively little interaction from other mods, and the problem is just one of scale - your huge play time has exposed a bug which I've never met before.

Yes I did one large bomb (the 5 tritium canister one) I believe that was 100kt) But it has been many hours since that and several game saves.
How do I get a save game copy to you ?
Thanks for your help.

Hmm.
Good question. You could send me a PM in the forums, and attach the file.
My profile is:
https://forums.factorio.com/memberlist.php?mode=viewprofile&u=108103
Same name (BicycleEater)

Although I've never used that feature, so I don't know if it will work.

I sent you a PM but it would not attach a game file, maybe too big ?? Check your inbox.
I forgot I did a game save before I set off the 100kt bomb, I loaded it and it's running at 60fps with ALL mods active.
There is definitely an issue with setting off the larger bombs it seems. My main game save was after the 100kt explosion
and it seems that was the issue causing the stuttering and slower frame rate. Still hoping there is a way to fix it, I'd rather
continue my main game than going backwards to an older save.