Sorry for making all these requests, I know you have enough on your hands without people stirring the pot but I may as well put them out there as I come across them.
Pretty much as the title suggests - currently translation Graph Curves are XY, which is ok much of the time, but it becomes a bit of a problem if you need to do Y only ease-in, for example - think bouncing ball, linear X and bouncing Y.
It would be good if we could have three toggle icons in the Curve panel: XY | X | Y
A workaround is to use seperate bones for x and y movement, but that's fairly messy and unpleasant. 😉