I rolled up a Prootwaddle once...
Anyway, I'd say it depends on how Your gameworld has been set stat-cap-wise for races with realistic capping humans at 30 or so while heroic Conan types are capping higher and yada.
Increase IQ is a 4d6 risk against ST I think if more than 6 doses are imbibed in a month elseif -1 IQ perm which might apply
Also requires 1 fresh human brain
Also any attribute can magically increase by a maximum of +5 with aid and potions etc adding on but not other magic enchantments as I recall ergo a +1 gizmo and a +2 doodad don't add to +3 instead the plus two doodad drowns out the gizmo +1 fwiw
A wish is limited to no more than 16 for a stat which "I" read as human w/stat cap @ 30pts or just over half max but that's reading into it a bit isn't it?