I'm guessing this is a D&D thing and not just Larian but why can't you "upscale" a "created" pact weapon as you level? Like create a +1, +2 or +3 version of the creatable pact weapons as you scale in level? Sure they'd just be basic "plus" weapons with no special abilities and there's better weapons to get, but it's be nice to be able to do so. I've often thought about doing a run where you have to use the gear you start with through the whole game. meaning your armor and weapons. Yes you can add any item that you don't already have filling a "starting gear" slot. Like rings, amulet, helm, etc. Could be a challenge.
It would also be very cool to be able to create pact weapons with special damage or abilities added in exchange for a + value. Like if you could make a +2 pack glaive you could instead make it just a +1 pack glaive but adding 1d4 of a type of damage. Just thoughts if someone wants to make a mod for this, I'd love it.