I have a bit of a dilemma with my DIY NAS rig.
Does your setup have any way to do noise insulation? I suspect the answer is no but figured I’d throw it out there, surprisingly noise insulation helps more than you’d think. I have a bunch of drives inside a desktop case with insulation panels built in and the drives themselves are in there with rubber anti vibration screws/mounts. Barely ever hear anything from the drives (granted my WD Reds are probably quieter than your current Seagates).
Just something to think on whether it’s an option for your current NAS rig or a future configuration.
Nouveau seems to work pretty well on Debian 13 for me, at least for standard web browser / streaming / video playback with 2160p HDR tonemapping. Back when I was using Debian 12 Nouveau would lag badly during 2160p playback so I was force to use the Nvidia driver binary at the time. But so far it’s been alright, granted I’ve not tested any gaming and perhaps that’s where Nouveau won’t do as well.