Which by the book I can't see why you wouldn't. Even in 2024, pact magic slots can hold sorc spells, and nothing in the Sorc font of magic description specifies "sorceror slots" just "spell slots". Warlock slots are still called spell slots, there is no language differentiation made.Only if you allow using pact magic slots for sorcerer abilities.
When you look over the multiclass rules, once spell slots are determined, there is no longer any special notes about slots, its all jsut one pool, you cast any spell out of any slot with no restrictions. The only note is that the spell itself (aka what class it came from) determines the spell casting stat you use, but that has nothing to do with the slot itself.
I can see the debate on vagaries in the middle, but I think reasonable interpretation points to you can more than you can't.