After Funcom have patched Dune: Awakening quite a few times since release, the experience on Steam Deck is now good enough that it's been Steam Deck Verified.
Easily one of the best MMOs released in a long time, I've been having a seriously good time with it, although it's a huge time sink. The initial release worked great on Desktop Linux but was just a little rough on Steam Deck. Seems now though Valve felt the issues it had that kept it to a Playable rating have improved enough.
As of August 18th, it's Steam Deck Verified with Proton 9.0-4. The developers also put up an announcement for the change on Steam:
Greetings Sleepers,
We’re excited to announce that Dune: Awakening is now fully Steam Deck verified!
Until now, it has been in the Playable category, but after some tweaks, it now meets all of Valve’s requirements to be a smooth experience on the Deck:
All functionality is accessible when using the default controller configuration
This game shows Steam Deck controller icons
In-game interface text is legible on Steam Deck
This game’s default graphics configuration performs well on Steam Deck
So put some Dune in your Deck and bring a little spice wherever you go.
Thank you all so much for your support as the team continues to work on improvements. Any issues you report using the in-game tool and feedback you leave across all our channels is massively appreciated! We look forward to sharing more details about all the new content we have in store for Dune: Awakening.