HypCo says:
Posting here to not break the dojo rules.
Not that it matters too much with a Nat. 20 but picking locks isn't a Sleight of Hand, it's just a straight Dex. check, adding your proficiency bonus if you are proficient with thieves' tools. Sleight of Hand is more taking gold pouches, concealing weapons, and planting objects on people.
True. I can see a few cases where it could change someone effectiveness at picking locks, but not substantially (personally). *shrugs*
If not proficient in Sleight of Hand OR Thieves Tools: it becomes a straight Dex roll.
If proficient in Sleight of Hand but NOT Thieves Tools: it's Dex + Prof. This could be problematic. (By using just SoH, they are now allowed Prof, so they are stronger than they should be by RAW)
If proficient in Thieves Tools but NOT Sleight of Hand: it's Dex + Prof. This could be problematic. (By using just SoH, they are not allowed Prof, so they are weaker than they should be by RAW)
If proficient in both Sleight of Hand AND Thieves Tools: it's Dex + Prof.
I can see a small case modifying portions 2 and 3 above for rogues and other classes (like a bard) that get to add Prof to their skills in other ways (2x for rogues on select items, 1/2x for bards if they aren't proficient at all) where it could modify.
I can change for the future for sure, but at least in this case it didn't actually have an impact on the result.
:P