Here's something promising for the future of cross-platform mod support, as it seems the Nexus team are working on a new Nexus Mods App. It's in the very early stages (pre-alpha they say), but eventually they plan to have it replace the popular Vortex but it's quite a long time away from that just yet.
While Vortex is popular, it's not supported on Linux / Steam Deck and so you need some workarounds with Wine / Proton to get it working. Having one of the most popular modding sites like Nexus actually have an official Linux modding client would be a nice big boost.
So why are they re-doing their modding app? As they mention on the GitHub page they now have a bigger team, and they plan to implement a lot of the lessons they've learned while developing Vortex into this new Nexus Mods App and the idea of easily rolling-back sounds good:
One of the biggest complaints of users over the years about mod managers is that they can't mod with confidence. Will a new mod wreck their existing install? Will copying some files into their game folder require them to delete the entire game if they want to revert these changes? The game updated, and the user updated their mods, now nothing works! Every step of the modding process is fraught with pitfalls and destructive changes.
The Nexus Mods App intends to solve these problems. In addition to being a great mod installer, manager and builder, this project aims to always provide an "undo" feature for users. Not just on a metadata level (like most mod managers offer today) but on a per-file basis as well. So go ahead, update that mod, if you don't like it, you can always go back to the game as it was before you made the update.
In regards to Linux support their FAQ mentioned:
Q: I see tests run on Linux, Windows and OSX, are you targeting all those platforms?
A: Yes, the CLI runs on these platforms and we run our CI on each of these OSes. What games are supported on these platforms (e.g. do we support Skyrim through Wine on Linux?) is yet to be determined.
You can find it on GitHub and it's under the GPL license.