This is so very nice. OpenBSD added support (in current) for booting from RAID1C; specifically, they modified the bootloader.

OpenBSD could already boot encrypted systems but not encrypted RAID1 (RAID 1C) via softraid. In their next release version, it'll be possible to do this.

https://www.undeadly.org/cgi?action=article;sid=20220813110021