Vertical Metrics Metadata in Static vs. Variable fonts

HI There!

I have a question about vertical metrics metadata info, and variable/static fonts.

I have seen this topic mentioned here from time to time in past posts, but I’m unclear after reading those threads, on what the resolution is at the moment.

I am familiar with the idea of, for instance, setting values like winAscent and winDescent on an individual instance for export, via Custom Parameters.

Let’s say I did so, and exported static fonts, which then reflect those values.


What happens if I then export a variable font of the same .glyphs file?

I presume the winAscent/descent values I just set are not present in the variable font file, because there was nothing connecting those metadata values to the masters?

Is it possible to set these values at the master level, and have them interpolated across the variable font design space?

And if so, is it possible to have the static fonts inherit those interpolated values, or do the static fonts still require them to be set instance-by-instance?