for those like me curious to know how's the Linux build coming along:
In another kind exchange of e-mails with the 3DCoat Linux developer he confirmed that a Linux executable of the program developed under Ubuntu 20.04 already exists.
Asked about an estimate ETA for a release, he then explained explicitly the couple of hurdles yet to overcome. Before those specific issues are dealt with he naturally wouldn't commit to a prediction of a release date [because it wouldn't make sense].
Still, to me, great progress has been made. I doubt we'll be waiting for much longer. Things take time and it seems it was well spent until now.
By the way, he even showed proof of what he told me, which was not asked but welcomed anyway, of course.
I am eager to try all the goodies other versions have and tried.
Good times ahead.