If you're like me, and you play Starsector on a ridiculously weak as fudge laptop, then you've surely dealt with the MASSIVE frame drops every single time you encounter anything larger than a pirate attack fleet. Over the time that I've played this game, I've seen some workarounds to at least alleviate the problem and have Starsector run consistently (and if we're talking about adding mods, which you will surely do sooner or later, you're gonna want the maximum amount of mods you can add without the gameplay becoming a slideshow picture of your ships getting wrecked.) Besides playing in the LOWEST possible settings here are some of the things that I did that *could* help you as well.
Keep your max fps to 30. If you can stomach it, you can lower this even further to what you can stand.
Disable sounds. Yep. Disabling sounds entirely from the launcher allowed me to play with mods/mod combinations that would otherwise be impossible.
If you can't stand playing without sounds, you can manually edit one of the configuration files in the Starsector folder and make it such that ALL fleet interactions use only one sound. This holds true for mods as well. It's a bit boring and repetitive, but hey at least you have sounds.
Resize the background pictures to something smaller. Travelling around the sector and going jumping from hyperspace to system always crashes my game. I resized mine to half the size using Paint. So there's that.
Do note that these are just personal changes to my game that helped me get that few MB's of RAM to squeeze in just a few more mods. If you've found other ways to do this, please do share it with the good craptop users here.