I suspect a hardware problem on an EA7500, and would like to move to another hardware platform, likely with the same version, 23.05. if the hardware is different, can/should I
Restore a backup from the old router to save the configuration
You can see what a standard backup would keep if you run
$ sysupgrade -l
Also, you can save all of that into an archive with this, then copy it off the router.
$ sysupgrade -b my-backup-file.tar.gz
If you are going to different hardware and/or a different OpenWrt version, you should start from scratch on the new router and use the backed-up config as a reference. Too many little things might go wrong if you just plop the old stuff on the new device.