I have a 95kg mate, he is an experienced racer. I've seen him use 11m sail on a 105lit hyper, 8.8 sail on an old, narrow 95lit Thommen slalom, and four-cam 6.7 North Warp on an 87lit Kombat (I've tried some of these combos). All this was for fun of course, well- to overpowered, and I'm sure there was no gain in early planing, while the handling was terrible (sinking up to his crotch in lulls). He was also much faster with appropriately sized rig (for the conditions/boards).
Not recommended under any circumstances.
I'm very much surprised sType105 is usable at all under a 9m. I thought for most people it's a 6-7m board.