well diskletters/numbers can change between boots and hardware configurations, and unless you have a good label for the partition, this is the only way I can think of to name your permanent mount points that isn’t problematic/incorrect in some other way. This will always work correctly with any amount of partitions with any amount of disks; and it’s not exactly hard to get the DUID of a disk, at least on OpenBSD. It’s also highly scriptable as such.