I have set up an lts kernel in addition to the zen I use by default. See:

https://wiki.archlinux.org/title/Kernel

Disclaimer: this only works when something with image creation goes wrong with an update. Which didn’t happen to me ever - unless I did a mistake or tested some kernel stuff. I only had bootloader errors when I screwed up pacman though. The fallback kernel in that case is on a USB stick…