Thank you! If I had a nickel for every time I'm told something I'd like to try is "uncommon" I could probably buy SideFX.
Unfortunately, though, I'm unsure what value to draw from that...it doesn't really dissuade me from needing to do the thing I need to do, which is to dynamically change the UI. Specifically, I am trying to design a colorpicker of sorts. There are no "menu" item options for the color UI widget, so I'm trying to hammer out a way to represent the various colors I want to offer as choices by way of a multiparm, then allow a user a way to choose which color they want to use.
I see there was a comment (now deleted) suggesting running the code on the HDA definition itself, rather than a node instance of the HDA, but I worry that would run into the same issue @ajz3d is describing (updating it in one location would propagate to all created node instances, rendering the operation useless).
The solution proposed by @EJaworenko does seem to be a likely path forward, though I find it kind of confusing (particularly for my future self...I will wonder why I had to do it this way). It seems odd to me that I have to do it this way.
Anyway, thanks again for humoring all this!