A little better than how you'd handle having multiple '/home' lines in fstab? Either pick one to mount, or have the bootloader give a hint as to which one to mount (as there's apparently a whole protocol the bootloader
must use for this to work). [0]
But. Having said that, why would you have two home partitions on other disks? Having a bigass disk for your home partition [2] is way more common than having multiple entirely-independent Linux installs that you all want to use this automagic mount point detection on. Do you disagree?
[0] > Note that automatic discovery of the root only works if the boot loader communicates this information to the OS, by implementing the (Boot Loader Interface)[1].
[1] <https://systemd.io/BOOT_LOADER_INTERFACE/>
[2] ...because where else would you store all your porn?