Good read, and I think you might want to look at OnlyOffice. It's open source and while it is kindof a shameless Microsoft Office clone, it does seem to support LaTeX when adding equations. Not sure how well it works as I don't use it though. The slides app is pretty decent, the only bone I have to pick with it is that there aren't many animation types and most of them are very basic. Otherwise, might be what you're looking for.
Edit: I just tried it and it seems to work pretty well. Select LaTeX, type your equation, then select professional in the dropdown menu and it'll show the equation.
So much great stuff in this release. I've been looking forward to single-threaded web builds especially, but other things like the new project manager are good changes too.
Lots of great QoL changes and bug fixes as well, like the "is not" operator and being able to loop audio via audiostreamplayer rather than on import. Good UI changes like being able to reverse flow container direction and indeterminate progress bars too.
The wait for 4.3 continues...