No, I don't use that mod, but I do use Ariphaos' Unofficial Patch mod. Possibly that helps reduce lag too.

does it also help with a big fleet window? I have massive lag with many fleets screen

No, not really, this mod, if you have the every 14 frames version, would only cut the load caused by the outliner refresh by 1/2... it makes it stutter a bit less in late game though. I tend to stick with the 56 frame version, even though it makes the outliner lag a bit. If you have my other StellarStellaris mod, that may be helping significantly though.

I find it puzzling that lots of others are talking about severe lag in 3.3.3, yet it doesn’t happen to me, despite me having a very old computer. Could it be because of this mod?

Yes, of course. I never close the Outliner itself... Also, does this mod work with 3.2?

Yes that is true, but be sure to close the outliner sections, not the outliner itself, as the outliner sections can be "open" even when the outliner itself is entirely closed.

One tip I've had, is to close most of the tabs in the outliner. I usually only keep 1 or sometimes 2-3 tabs open at a time.

Towards the late mid game, depending on how much I expand, I also close most of the Sector sub-tabs in the Sector tab. This is supposed to reduce lag, and ought to synergize with this mod.

You can do either, this is a totally separate piece of functionality. It just lowers how frequently the outliner gets updated. In late game with lots of mods, you can experience a significant lag spike when the outliner updates.

I don't really understand the description, am i supposed to use this with the normal StellarStellaris mod or do i only use this?

No problem, I literally did nothing.

Thanks for updating this mod!