Comments from playtesters
"I prefer the way it works in Blades because it's known and easy to follow. It gives an almost numerical value that lets the player quickly understand and cuts down on the need for negotiation."
"I’ve been playing Fistful of Darkness and my group and I often get caught up using Blades terminology—even the GM—which is mostly confusing to the one player that had never played Blades."
"Yes, I prefer the way it works in Blades. Just familiar."
In light of this, I decided to modify the approach to determining effect and position - and leave the underlying system of controlled/risky/desperate as is. Now players will say what they are doing, and the GM will clarify if needed "What do you hope to do? And what do you most fear will go wrong if you fail?"