edit: as an afterthought, could i go the other way. instead of coming down in board size to tie in with the 6.3 / 7.0 on the old f2 ride, could i "bring up" the small board size by looking at, say, the carve 111?.
If that board works well with 6.3 and 7.0 and perhaps the occasional 7.5, 7 batten RAF, then a carve 111 / go170 combo could work well. i get to keep the trainer. i maintain my early planing threshold, and i get a "jibes itself" board.....