Just to make clear: I'm converting APHEELSIK on sight right now. If I literally have no other useful glyphs I might keep it temporarily, but against any relevant foe it just times out way too quickly to be worth the MP. For low-level characters it's ludicrously weak; BURDAYRAZ and HALPMEH are way better for regen-fighting purposes, since APHEELSIK times out much too quickly. For high-level characters, exploration space is mostly depleted and at a premium and poison has highly limited applicability.
What annoys me most of all is that this change has effectively killed many of the glyph combos that formerly existed with APHEELSIK. Fireball/poison? Good luck fuelling that even with BLUDTUPOWA. Poison with LEMMISI or HALPMEH? Much too mana intensive. ENDISWAL/poison? That's a pipe dream. CYDSTEPP/poison? Just cut out the poison entirely, you're better off just specializing in damage spiking. You simply cannot regenerate your mana while maintaining poison against any reasonable foe, which renders pretty much every glyph combo with APHEELSIK non-operational.
One of the cool things about poison was that it opened up a wide variety of combos, and if you were willing to sink the exploration into fuelling them you could do some pretty amazing things. In a typical dungeon run, this could mean killing monsters up to 4 levels higher than yourself. In the most extreme, tweaked-out scenarios that meant a level 1 boss kill (which only works against low-HP bosses) on the easier dungeon in the game. I feel that to deal with a very niche scenario you've ripped up a huge amount of variety surrounding this glyph. In most cases, APHEELSIK did nothing more than what was possible with damage-spiking strategies.
With that said, I think this is the right direction for dealing with on-attack poison (it just needs to scale with level, like lifesteal does), but for the glyph this isn't working for me.