So as far as I can tell, the Sorcerer just has a flat +4 HP cost for BLUDTOPOWA (so at level 1 it's 3*1 + 4 = 7 HP, at level 10 it's 3*10 + 4 = 34 HP). Amusingly enough, despite the penalty being quite stiff at level 1 (and fairly inconsequential at higher levels) it's still possible to get level 1 boss kills, because your net HP gain from casting glyphs outweighs the HP cost from BLUDTOPOWA (spend 1.75 HP to recover 1 MP, spend 1 MP to recover 2 HP). It's just harder to pull off, since you need a high enough max HP that you don't waste any of your recovery - you need to consistently get the full +12 HP from casting BURNDAYRAZ to make the combo work, which requires a max HP of 20+. Or just use PISORF, maybe, although that requires even more scumming (since prepping Binlor generally leaves you with too few walls).
I don't know that it's actually worth the effort of fixing, since it's such a niche case and requires copious amounts of scumming to make it work. Even a Dwarf will have trouble getting enough max HP, since his HP bonus sucks at level 1, so you'll basically need to find either JJ or Earthmother or a pendant of health and BLUDTOPOWA and still have enough tiles remaining to kill the boss. Possible but scum-tastic, and certainly no easier than the other level 1 boss kill strategies. (Basing the Sorcerer's HP recovery on character level would, of course, eliminate the problem altogether...)