What actually got me a working device again was to reinstall swmo edge. ~sxmo-build/sxmo_build_all.sh --wayland
The workaround mentioned above does not really fix things, I have a very broken system after that. Menu does not open, keyboard is all garbled. I think it's a half sxmo, half swmo Frankenstein's monster.
I looked through https://github.com/postmarketOS/pmbootstrap/issues/952 as suggested and tried this https://lists.alpinelinux.org/~alpine/devel/%3C20171231150048.044adbf9%40ncopa-desktop.copa.dup.pw%3E but at least after the workaround no ERROR was found.
Workaround was: apk add postmarketos-ui-sxmo-de-dwm tinydm-set-session -f -s /usr/share/wayland-sessions/swmo.desktop rc-update add seatd default
I played with this a bit two weeks ago. I changed the "take picture" button to volume_up rather than power button. The phone still did not come up from crust, so I think it is not due to the action handler.
I think ~proycon did fixes for this issue a few weeks ago. There was a missing newline and numbers were written/read in multiple different ways. I'd say let's close this one.
I have not seen this happen in the last month, so I guess we can close this ticket.
I'm pretty sure I've had this happen plenty of times with touch input keys, which would speak for a software issue. If it is a hardware issues, other distributions and DEs should suffer from it too. Also we should never assume that we are dealing with just one issue.