Is there an idea or something I can do to copy my current partition to partition 2 of a 3200acm?
Luci-app-advanced-reboot allows me to reboot into the other partition, but what if I need to backup my current partition to the backup partition?
It would be very useful in a situation where you just did reboot to the backup partition, you fixed the issue, but you can't reboot into the other partition because of said initial issue. I could just say make partition 1 partition 2 or partition 2 as partition 1.
I wouldn't expect that to be added to luci-advanced-reboot, while it might semantically appear like a matching feature, it would need to work at a much lower level (it also can't really copy the overlay of a running system, as files might change during the process), duplicating very device specific sysupgrade functionality - compared to 'just' reading some kind of flag and toggling its value (and adding a nice GUI on top).
From a functional point of view, this isn't really a great strategy either - you usually want a known-good (older) firmware on the other partition, in case your newer one fails (e.g. while upgrading (failures in sysupgrade have happened, so this is not theoretical), your old install already proved that it was at least good enough to install a new image, your new one has not).