Oh, I totally misunderstood the OS. I was under the impression that using os-tree should be totally avoided for anything other than necessary system programs, and all other software should be installed with flatpaks or containers.
I now understand that using os-tree for some programs is inevitable, and I should embrace it, though still catiously to maintain as clean of an OS as possible for maximum longevity.
Honestly, I just followed the steps here: https://rpmfusion.org/Howto/NVIDIA#OSTree_.28Silverblue.2FKinoite.2Fetc.29
I was diligent about following the configuration guide first: https://rpmfusion.org/Configuration
I think the key is restarting at every step it asks you to, and maybe after anything that seems major or is a prerequisite for another set of program installs. I mean, I got a black screen the first time, but after a hard reset, it just worked.
No doubt UBlue is probably a lot easier. I did not realize I could have just downloaded the ISO instead of trying to rebase, but I like what I am running.
Anyways, doing it the hard way is helping me learn the intricacies of an immutable system, so I am having fun.