MATE 1.26 now available for Ubuntu MATE 20.04 LTS and 21.04 (PPA from Martin Wimpress)

Can someone give some pointers to how should one update/rebuild these packages that are in ppa:ubuntu-mate-dev/fresh-mate repository ? What would be the best way of doing that?

Of course I can research it but it will take me hours or days.. if one already knows the answer I would appreciate it.
I'm on Ubuntu Mate 20.04 . I can't find any alternative repository that would have Mate 1.26.1 packages.

Solved, I've put together a script that builds most of the packages from upstream repos: https://github.com/torson/mate-desktop-build .