Linux 101 stuff. Questions are encouraged, noobs are welcome!

The number of issues I've been having with Bazzite, due to its immutability and my lack of experience, has finally reached the point that I'm no longer willing to deal with.

But I like basically everything about Bazzite, aside from its immutability, and I'd like to preserve as much of it as possible. In particular, I like KDE/Plasma (right?) way more than I liked Cinnamon on Mint, and the whole reason I gave Bazzite a try over Mint was that it supposedly was better for NVidia gaming. Which has absolutely been true, all the minor performance issues I was having on Mint vanished under Bazzite.

So, thoughts and recommendations? Thanks in advance.

Since I'm sure some nerds like me will want to know WHAT issues I've been having, the most significant ones would be....

• I've hit a dead-end with trying to setup multiple audio sinks, so I can do what's been standard behavior in Windows for decades and use both my speakers and headset separately, at the same time, per-application. There's basically only ONE source of info on how to do this, and it's written for mutable distros, as it apparently involves doing some firmware config mods or something.

• I've had quite a lot of issues with getting JetBrains Rider and the .NET SDK to work properly with each other, ranging from the inability to get .NET 10 installed, since Rider's flatpak only includes up to .NET 8, and there IS no flatpak for the .NET SDK itself, to getting .NET CLI tools to run properly from Rider, due to the sandboxing.

• I was looking to install GameMaker to continue a little side project I started on Mint, and it's not available on flatpak, nor can I find any wisdom on how I might work around that fact.