I do not experience the behaviour with the cursor, but when a game in fullscreen doesn't play nice, I move it to the second workspace (with a keybind) and then quickly switch to the first workspace with another keybind. Both are easy to remember and as fast as alt + tab.
I had issues with Onlyoffice taking ages to load documents with lots of pages while Libreoffice did it instantly as expected. So back to Libreoffice for me.
Oh my, you are really patient for putting up with all this for such a long time. Yes, I have slightly different components, not the exact same ones, but it was also a mess to get it to work properly.
Sorry for not answering your question, just wanted to say, I have a similar HP Laptop bought under similar circumstances and it IS Linux unfriendly (you cannot even update the BIOS without Windows). But Linux Mint handles it very well. It was the first distro that got the WiFi working without headaches and it also handles the AMD card well.
I hope someone can answer your actual question and you get something you're happy with.
Great and very informative read, also good advice for people who want to contribute but aren't able to write code.
The blog post is about KDE of course, but I think the idea isn't limited to that project. There was this post on Lemmy not so long ago where people were discussing other ways of contributing or how people help with open source projects. And there were quite a few who said they can't code but would like to help with other things (apart from donating money).
Many games with anti-cheat work, a comprehensive list can be found here: https://areweanticheatyet.com/
Anyway, I wouldn't install a rootkit "anti-cheat" on a Windows machine under any circumstances, but that's just me.