With the exception of stable, which is on core20, all Chromium channels use core22 as its base snap.
It would be very helpful to know about possible regressions that automated and manual tests did not catch before releasing it to stable, which is the channel that the vast majority of users track.
If you would like to help testing,
snap refresh --candidate chromium
and then use Chromium as you normally would.
You could also use parallel installs by the way.
To revert that action after done testing (if desired),
snap refresh --stable chromium
Apropos: The first paragraphs of Chromium maintenance notes explain what are stable, candidate, beta and edge channels in Chromium.