Im guessing this will be possible but is it something that will need the construction kit to create?
It's really needed as at the moment (as long as you have enough potions in your inventory) you're pretty much invincible (Unless you get one-shotted of course).

I would love this! Am trying to resist the temptation to drink healing potions in combat, as it feels so cheap right now.

Generally I think every potion should have a short 'readying time', or something... so that, if you decide to poison your axe halfway through combat, you have to stand still for a moment. Anything like this would make it far more important to be prepared, and time your advances.