https://github.com/MarlinFirmware/Marlin/pull/11132/files
This pull request seems complete other than some config files that need updating, and I think these are done with a script. This would really help with the last major issues with the Archim1 firmware changes. What is the proper way to offer my help or give this a nudge?
I think posting a comment, giving a thumbs up, or just commenting, “good work, I think this would be good for the archim boards” is enough. It probably just needs some activity to get back in the top of the queue. I would avoid asking, “when is this going to get merged” or even “what’s stopping this”. I would even avoid asking if you can help unless there’s something you really think you can do. It sounds like you think it’s ready.
I would update the configuration files (including copy of the comments that are only on the first one IIRC), and add te information that it is useful for an incoming Archim board support.