Vertical fill on Perspective Progress Bar Possible?

In perspective, is it possible to use vertical fill on the progress bar without having to rotate the object?

No, rotating the component the 270 degrees would be your best bet.

But you can make a feature request to see if that particular feature can be added in the future. You can submit your request here - Ignition Features and Ideas | Inductive Automation

What’s the problem with progress bar rotation? It seems to be the sensible way to do it.

It may be possible to do what you want with CSS injection. The standard progress bar actually has a full-width bar that is moved left with CSS transform: translateX(25%) to give a 75% display. I don’t seem to be able to add in a translateY() instruction.