After reading the URC manual for my mx900 I can't find a way to program the volume buttons for both a quick press for one step up or down, and press and hold for continued volume up or down as long as it is held.
The manual's press and hold instructions are for something completely different that I don't need.
Not sure if it's even possible, but I would like to use it if it is available.

Can you explain the usage case? That's normally how volume buttons work by default.

If you are asking to make the volume button make a small (single step) adjustment with a quick press, but to make a continuous adjustment with holding it down, you don't have to do anything...that is how most buttons default.

If you are asking to make a quick press do one function and a long press to cause a different function, that is what the PRESSHOLD features in CCP is for.

If you ever want a button NOT to do the first thing above, you turn off the "Repeat button while pressed" setting by double clicking on the "step" you don't want to repeat in the Macro panel for that button.