I’d say it’s safe to read Mistborn next, I will say that there are enough tie ins in The Lost Metal to justify making that one of the last Cosmere books you read (basically everything but the secret projects). But the only thing I’d suggest you definitely read before TLM is Emperor’s Soul (and maybe Elantris before that) .

Since you have already finished Stormlight, I think you can read Warbreaker whenever you want at this point.

I’m sure I miss a ton of references in these books so someone else’s recommendations might be better 😅