I've updated to latest wlroots/sway and now imv segfaults immediately, whatever image I try to open:
imv Downloads/screenshot-2021-12-13-19:58:23.png listener function for opcode 4 of wl_output is NULL  347009 abort (core dumped) imv Downloads/screenshot-2021-12-13-19:58:23.png
imv shouldn't be binding to the latest version supported by the compositor, it should be binding to the latest version it supports itself.
Thanks for the report primalmotion, and also for the advice emersion. It was very helpful in fixing this quickly.
I've pushed a fix to master (c7306a63). I've also applied the fix to the latest stable release and have pushed v4.3.1 as a hotfix.