No, I'll be using Proton. There's a chance it won't work day 1, but I find it unlikely given my experience lately.
Especially with shader caching, it's even possible that it runs better on Proton while bugs get worked out (that was the case with stutter in Elden Ring, which didn't occur on Linux or Steam Deck with shader precompilation).
To me, playing a Bethesda game for the first time feels wrong with mods. I definitely want to experience the “original” at least one time before changing anything.