I know they are compatible with the "Spyder5".
Yes, DispalyCAL is compatible with Spyder5; it automatically recognizes it and downloads the specific "corrections".
I am very satisfied with it, I have calibrated all my monitors to the "Rec. 1886" standard offered in the menus.
My main doubt is whether I have to remove the current ICC that runs on my system before doing the calibration. Ideally, the software used should
then be corrected individually if it supports the option. Right now, I don't think Cinelerra can.
I think CinGG doesn't have a real color management (as Olaf pointed out some time ago). I don't think it's easy to create it. Maybe by implementing OpenColorIO (http://opencolorio.org)? It seems to me that you know the subject well, do you think it's possible?