Use the backup-tool you know, it’s always a good coice. If something went wrong, ’eos-shifttime’ may be your friend.
You can install another kernel to have a second one (i.e. LTS or ZEN).
And it’s always a good idea to read the https://forum.endeavouros.com/t/a-complete-idiots-guide-to-endeavour-os-maintenance-update-upgrade/25184 from @fbodymechanic and the https://forum.endeavouros.com/t/how-to-run-a-stress-free-endeavouros/49769 written by @dalto.