Alright; so it's legit for a kitbashing enchanter (a pregen I'm building for convention one-shots) to have a bunch of vials of low strength superglue and acid, even with only two slots committed for potion use?
It's also in the fiction and in the rulesbook that Harry shared the Escape potion with Susan, which in that case lowered the duration of the effect, but did not dilute the strength. But we can no doubt shift duration around with relation to item strength, so I'm assuming some flexibility there. So, as with other enchanted items (as folks noted above) you should be able to lower the effect down to the minimum of 1 shift of power, and each shift sacrificed is another use of the potion or item.
If the kitbasher only has Rituals, then the Specialization bonus wouldn't apply, so that would be:
Lore +5
2 focus item slots from the Rituals ability become 4 enchanted item slots.
Base complexity of a potion is 5.
Which means that for 1 potion slot, the kitbasher can have an Average 1-shift effect, 5 uses.
The rules as written indicate that sacrificing a second enchanted item slot only grants another use, so the kitbasher would be better off making another batch of an Average 1-shift potion with 5 uses.
So theoretically, that kitbasher, assuming no specialization, could have 20 total uses of an Average-strength 1-shift potion. The kitbasher could have 10 uses each of two different potions (10 of superglue, 10 of acid), or mix it up in other increments of 5.
Edit: this seems to be getting potentially abusive - what do other folks think?