AFAIK geom_vinum was updat­ed for FreeBSD‑8. I can not remem­ber to have seen a post about geom_raid5 on current@ or hackers@. Do you have a point­er to a dis­cus­sion regard­ing this on a pub­lic FreeBSD-mailinglist? If this was not dis­cussed on a FreeB­SD mail­inglist, I sug­gest to start a dis­cus­sion there.