[FEATURE REQUEST] Curve Editor - shortcut/button to lock key movement horizontally or vertically

[doC]

Would find it very useful to be able to lock the movement of the keys on the x and y axis.
Currently when editing a more complex curve and I want to shift some keys in time, I usually also affect their values which messes up the precisely set up curve.

[doC]

Oh dear, why does this keep happening... I tried a few keys, had a look at editor input configuration, checked the documentation and didn't find anything. But I had to miss the one button that already does this - shift. Sorry for the lame request