FR: lock pitches, record live rhythm?

Part 2 of the Alan Silvestri interview mentioned his delight at being able to play the rhythm of a complex part “with two fingers” on a MIDI keyboard into Dorico, and then repitch the notes.

It occurred to me that for realizing music from an existing score, the inverse function would be just as useful: “lock” the written pitches, but play the rhythm in live.

A sort of “unquantize” capability, but with human input, not computer generated humanization.

I mean changing the timing of each individual note, - not a “tap to create a tempo track” command.