Dear all,
I'm using a full Wayland plasma session in KDE on Slackware-current for months now and it had been a rather good experience. Even activities are working fine now and all the applications I use work flawlessly.
I have just one issue that bites me once in a while : kwin_wayland sometimes crashes completely (and all the programs with it including bash shells running in Konsole) when closing a tab in Firefox.
I usually get messages like this one in the dmesg:

messages:Aug 15 16:55:16 coyote kernel: kwin_wayland[2389]: segfault at 3f302c000 ip 00000003f302c000 sp 00007ffc457f2238 error 14

This is quite close to what's reported in the following report (though it's for KwinFT):

https://gitlab.com/kwinft/kwinft/-/issues/222

I don't use debug KDE binaries so I'm not sure I can help in opening a bug.
Does anyone already experienced this?

I strongly recommend you to use the standard Wayland sessions for Plasma5.

The standard Wayland sessions are known to be more stable and less prone to crashes, because it leave at applications decision whether to use Wayland or X11 (via XWayland) as graphics system.

The full Wayland sessions forces the unconditional usage of Wayland and it's known to be less stable.

Also, as regular user, the full Wayland sessions gives you NO supplemental advantages - they are for testing Plasma5 as developers.