I’m not that deep into it and as you noticed information on the issue is sparse. My understanding is that it is not possible to get power management working for these cards (see https://nouveau.freedesktop.org/PowerManagement.html). May not seem like a big deal, but as far as I understand this means the cards are stuck in the lowest power setting i.e. perform as well as an iGPU.

And from my understanding this is forced by Nvidia because power management is disabled when loading unsigned firmware.

That is my understanding of the situation. Due to this the devs basically gave up on those cards as it is unfixable.

I am aware. Nouveau works okish with cards from the 800 series and older. It does only barely work with 900 and 1000 series cards, because of the firmware signing issue. You can check their page for compatibility information. And the new “open-source” driver only supports the RTX cards.

Nope, 900 and 1000 series have little hope of being properly supported. They require signed firmware which seems to be problem and are not new enough for the “open-source” solution from Nvidia for new cards.