Yeah I wasn't sure if the importer would even make it to the end of the import on a v3 database but to my surprise it did!
The number of tables on a v3 -vs- a v2 phpBB system roughly doubled. (37'ish to 62) on my modded v2 system there were an extra table or two over a stock install.
I'm biased of course so I'm really hopeful that someone would take interest in this project and update the script to address phpbb3 systems.
I really want to move this board to UBB.T and purchase another gold license... nudge nudge, wink wink...