Last weekend the beta version wich is supported of phpbbhs came out. Ik am running this script on forum (under construction) and i think it would be great if there would be a version of the modrewrite/zerodupe/optimaltitles for this hosting script. This would mean without admin options and i think it wuold be best if it can be done without database changes.
There are quite a few people who bought this script and i think it also has a LOT of backlink potential for you when you make this mod. Google see's subdomains as diffirent websites, so a lot of links from a lot of websites.
I know that you are really busy, and you recently got a new family member, but i think it would be great to have this mod.