One, picking the lock in a fail forward game is generating the result fully using a mechanic.
Two, a random table is the most quantum-like state imaginable, because unless it's the most heavily-curated table imaginable, it will contain results that are make far less sense than anything the GM is likely to come up with on the fly.
Three, while yes, some games, especially PbtA games, will say "on a 6-, pick 2: X, Y, Z
So basically a video game with a large but limited tree of options.
So something made up to fit the circumstances is inherently less plausible than something rolled on a table?
By what makes sense.
Or--and this is a wacky idea--saying, "Player, you managed to pick the lock but screwed up badly somehow in the process. What happens?
Get the players to tell you what their player did. If you don't mind them narrating their successes, why can't they narrate their failures?
My favorite line on a 7-9 (success but complicated) is the roughly “the GM will present you with a lesser success, cost, complication, or a choice between.”
It’s most fun for me to let them pick between the rock and hard place, and like you said sometimes say why.
I love seeing players being as creative as I am, and sometimes more so.