When you pick a lock, the GM rolls a pile of dice, and I don’t know yet how we add them together but we want to generate 1, 2, 3, or 4 numbers from adding those dice together.
The thief then comes in with their tools: A d4, a d6, a d8, and a d10.
If the thief is skilled at their job, the GM reveals the target numbers up front.
Your job as thief is to roll each of the target numbers in sequence without exceeding them. If you go over, your pick breaks or you lose your focus and you have to start again.
Maybe you can use some kind of resource to add +1 to your current total, or to cut a roll in half.
You can’t roll a given die again until you’ve rolled each other die once—OR the size of the die says something about the time it takes to make progress. So a d4 takes longer. More precision takes more concentration, etc.
Do this during combat to pick your lock while your friends are fighting off guards, maybe! Or during a Blades in the Dark score, racing against a depleting clock.
So make this faster you could just set target numbers from a table based on difficulty. You’re basically playing Black Jack with dice.
I dunno. Could be fun.
Also could see some in-game meta-wisdom from a grizzled thief NPC mentor, like: “Always start with your d10. If that first tumbler is higher than that you want to cut that distance down as fast as possible.”