@adamf, that very well may be sufficient to make hwaccel happy, as long as the drivers are also present.
In any event, I actually chickened out and switched the default for the new ffmpegHwaccel from auto to disabled due to failures on macOS, and the fact that it doesn’t seem to be a simple apt install something-something-cuda and have things work (at least on Ubuntu).
I’m closing this now to release the votes associated to this feature request. If you’d like to discuss this further, feel free to open a new topic.