Thanks for the tip, Burnrate.
As I had received no reply to my original post, that was precisely what I ended up with, months ago. I wrote a tick based time-driven code for managing curves that were manually linked to various UMG widgets’ properties. A bit messy and nothing by the book, but it saved the day.
Though not mandatory, I still would love to learn the formal way of creating runtime UMG animation using the Unreal Engine API.