Spent most of the day looking into options for this but came up blank

Bit frustrating as both the FilledSprite and the SplicedSprite functionality is there, I just need to be able to have them both.
Workarounds like trying to apply some sort of mask and applying the mask to my frame sprite didn't seem to work (as there doesn't seem to be any masking support - closest I found was using a clipping panel, but clipping is based on a rect so you can't do radial stuff like the FilledSprite)
So the best (only) option right now seems to be to add code to the UISprite so that additionally to the other types, it can also handle a SplicedFIlled type.
This too seems to get rather convoluted as the filling code in UISprite seems fairly complex and specialised to the current use cases that are handled.
I did spot the Advanced type too but again you can't seem to be able to have a radial type for the subtypes of the advanced type.
Failing all that are there any other suggestions on how to do this? Thanks!