Ruin Explorer
Legend
Even in blades the intention isn't that you don't plan at all, but rather that you plan but don't dwell on specifics and you skip the long run-up where everyone gets into position and whatnot.
Yeah, but that's like half the actual fun bits of the heist! People who don't like those bits are like people who cut the crusts off bread, don't eat the skin on chicken, and so on!

We played it a couple of years ago, and I was a player not a DM, but it was pretty aggressive about telling us not to plan, I remember that. Like, the plan seemed to be limited to "You know there is a thing in the place and now you will take the thing from the place!" then "You are in the place! GO!"
The example of the flashback given is a player comes across a safe but doesn't have the means to open it, so he pays the inspiration and flashes back and uses persuade to talk the combo out of the safe maker, essentially opening the safe with persuade.
That seems er, extreme but I guess if he explained it well enough I could buy it. What if he fails the persuade check, though? Or does it not work like that?
The one we used in the Logan Bonner adventure and a few others was more like you could say "Oh, I had this small barrel of explosives with me, as I planned, not left in the portable hole back at camp or anything like that!" or "Yeah the guard sees me, but I paid him off already, so he nods and moves on!".