Alright, when I have some time, I'll PR the addons so the arm32 devices will attempt to use the arm64 images, which will serve as a stopgap until LE12.
Keep in mind that we also have 32bit-only devices, with 32bit kernels (eg our RPi2 images which is used for RPi2/3 and which are still a significantly large part of our userbase).
You should also cater that, eg by not offering the ls.io addons/repo to those installations at all since it can't work. CvH can provide you info how to properly disable/deprecate/remove your addons/repo for those installations.
so long,
Hias