Currently the SVG export in Figma excludes any vector shapes that cannot be see due to a mask at the time of export.
I understand why this was an intentional optimization and I don’t see a way to disable it, but because it is useful for a niche use of SVG graphics I’m working on I wanted to double check and see if anyone knew of a way to change this behavior or work around it.
For example, Figma also excludes elements with a 0 width stroke or that are fully transparent, but that can be worked around by making a very small stroke or alpha (0.01). I can’t think of an equivalent solution for elements that are fully clipped by a mask.