Thing is, I have no idea how well "Bstinay" cones will work... or how poorly. Are they the right size, shape, and density? Replacing cones is not exactly reversible. Even somewhat degraded Roland cones are more of a known quantity.
Adding washers is 1/10th the effort of changing a cone, practically zero risk, and completely reversible. They can only possibly make things worse if you raise the cone too high... and that might also be a risk with some aftermarket cones.
I don't think there's any good reason *not* to experiment with washers if you're dealing with degraded sensitivity and don't want to shell out for 1st party. Worst case is they don't get the pad back to where you want it and you're out 10 minutes of time, and you can still order new cones.
