Custom Cresc./Dim. with a pre and post dynamic marking

It would be nice for crescendos/dimuendos to allow pre-/post-dynamics either to be shown or hidden (either as the default dynamic markings or with custom text in a dim/cresc text).
This way you could have a custom palette of dynamic cresc/dims from any dynamic marking to another, and stretching the cresc/dim (shift+l/r arrows) would expand the range of time it takes to get from one to another dynamic. Basically, this would cut the time required to input a dynamic marking then a velocity change marking, then another dynamic marking and make it one marking.

You can already create custom cresc/dims, but they are only of increase or decrease relative values without reference to an absolute value as in a dynamic marking; e.g., to be able to drag a crescendo that has with it a pp to an f and place it wherever and then expand it as needed later would be most useful as opposed to having to deal with three different markings. Is this already implemented and I'm overlooking? Any opinion?