I went from Arch to NixOS and I've been loving it. I also had all the time on the world to dive in with several machines to fall back to.
There are a lot of layers to wade through especially when you need a specific tool like your UE5 case. As others are saying, there are ways to make everything work, nix or non-nix, it's just more to work through after getting the bases covered.
Anecdotally, I had little trouble getting set up on my MSI laptop with an RTX2070, Primus and all. That was after learning the ropes on a Ryzen IdeaPad.
Rambling aside, I would definitely make sure to start in a non-mission-critical way, but do jump right in if you're comfortable. Maybe if you can stomach the Asus a bit longer, or get the Framework set up and play around with the Asus. And ask plenty of questions! I know I'm not alone in jumping in on nix questions any way I can :)
Another for Mull and Cromite, here. I don't really use Mull unless I'm looking for absolute compatibility with things like web games.