It seems to me it can already be expressed by inserting an extra slider leg in the same direction for making up the difference.
I don't see how you can express a shorter leg like that. I was thinking of something like dabaubR where each successive leg should not be longer than the previous. The only way that seems possible now is to do every possible combination of different numbers of W steps. But you understand it all better than I do
Another idea that's probably also too unusual to matter is to allow repeated p modifiers in a single leg so i could be applied to a move that hops over multiple pieces.
I don't see how you can express a shorter leg like that. I was thinking of something like dabaubR where each successive leg should not be longer than the previous. The only way that seems possible now is to do every possible combination of different numbers of W steps. But you understand it all better than I do
Another idea that's probably also too unusual to matter is to allow repeated p modifiers in a single leg so i could be applied to a move that hops over multiple pieces.