I updated this mod in the middle of an SE run and was running 2.3.3 for some reason. I've been playing with vanilla biter settings (much more difficult than SE default). I've been barely holding on and have to do bombing runs where I drop 500+ thermobaric rockets in a single run.

The 3.x update reduces the thermobaric rocket fire rate by a huge amount. Since SE locks actual nukes behind like 200+ hours of research, I'm stuck with thermobarics. Having to wait like 10 seconds between shots adds a virtually unplayable level of grind now. I do think that making the thermobaric rockets more expensive was a necessary balance change but the slower rate of fire is absolutely killing me.

Is there any way we can get a cooldown multiplier setting for thermobaric weapons? Setting the cooldown to 20% instead of 3.33% makes it reasonable again for me.

Hmm, the high-fire-rate rockets are the small ones, but they give the smaller explosions. To be honest I intended that players would use artillery or delivery cannons, or whatever other weapons system they want, with rocket launched thermobarics reserved as an early-mid game option, used sparingly as they are relatively expensive.
I could add larger thermobarics to the smaller rockets, as that would result in much more aggressive options for deploying them - maybe giving it a way more difficult recipe to compensate...
I'm open to other balance suggestions though.
I would also be very happy to move basic atomic weapons and atomic bomb into being easier researches, as they are intended to be relatively easily obtainable.

Actually though, maybe a really expensive large rocket large warhead thermobaric would be good. The reason for desiring a faster fire rate is due to it taking so many of them to kill oceans of nests which could indeed be solved by a more expensive but also more powerful rocket that carries a large warhead. I have entire oceans of rocket fuel to expend on the war effort, but I need my base to be hold together long enough to actually accomplish stuff on other planets whatever the cost is. Maybe make it take like 4 rockets, 40 rocket fuel, 1 large warhead and either 5 or 10 rocket control units.

Atomic bombs in SE currently need utility science which needs stuff from at least 1 other planet (possibly 2, haven't got that far yet). Maybe making it so that the most basic entry-level tier atomic bomb needs space science research instead of space science and utility science research would be good. In exchange for easier science, you could make it take 2000 or 5000 instead of 1000 science packs.

Overall, the player needs a way to kill enough bugs that you can go off-planet without bugs completely overrunning your base. It should definitely be expensive but still possible for when you have a high evolution and are out of other options. Whether that can be accomplished by larger thermobaric rockets, earlier nukes or both, i'm not sure which would be better. This mod is very generous about gameplay options so maybe you could make a checkbox for "enable large warhead rockets" and "first nuclear research doesn't need science from other planets".

I have no problem with:
- Moving basic atomic bombs, and atomic bombs under rocket instead of utility
- Adding a more expensive more dangerous thermobaric - think the artillery thermobaric, but as a rocket, and maybe the medium one as a high-fire-rate rocket.
- Both

I've completely reshuffled how the tech tree interacts with SE.
See what you think.

Overall this looks pretty good. I think this works out better since now it's possible to get atomic bombs without going to other planets.

One thing I noticed is that "large atomic weapons" requires space science and does not have the kovarex process as a perquisite but the "full fission weapons" test research does have kovarex as a prerequisite. Kovarex needs space science and production science which needs stuff from at least 1 other planet. If the intention is for the player to be able to build and use 1kt and 15kt nuclear warheads before going interplanetary, the most obvious fix would be to make "full fission weapons" not depend on the kovarex process being unlocked.

Overall, this is a positive change though. Thank you for your continued effort in working on the mod and keeping it updated.

That is largely deliberate - I wanted it not to be super expensive, but to encourage the use of smaller nukes for a while, but yeah, it was kinda weird, so its changed now - you'll have to remove/redownload the mod to get the changes, as the update is so small.
You should find the 20t big rocket devastating enough to fill the role you are missing.
And thank you, I try my best!

Yeah that makes sense. The 20t rocket is definitely a big one. Larger nukes aren't really feasible until you get the kovarex process anyway.

Yeah, that was kinda my thinking.
Anyway, you can now get the bigger ones, it will just be a pain to deploy them usefully without artillery.