clutter is unmaintained upstream, and is in the process of being archived
by the closest thing it has to an upstream maintainer. The most recent
major release was in 2016.

I am not aware of a porting guide.
https://gitlab.gnome.org/GNOME/Initiatives/-/issues/31 has some examples
of apps being ported away from Clutter/Cogl.

    smcv

Replied only for some days of delay of AUTORM and have a little more
time to carefully evaluate what is best to do in cinnamon when
eliminating caribou

I don't see any serious issues that would require removing it
immediately, so I would hold off until the end of the year rather than
leaving users without an on-screen keyboard in the meantime. If there
are serious problems I'm unaware of, making it worse than leaving users
without one, please let me know.