macOS ATSUI font services not recognizing Source Code Variable

Customer reports that after installing Source Code Variable and selecting it as the default font in BBEdit's "Editor Defaults" preferences, the font is not rendered in text editing views.

This is likely because the font is missing data that ATSUI (the macOS font rendering stack that BBEdit uses) requires; but I cannot speculate as to what that might be.

You can download BBEdit [here](https://www.barebones.com/products/bbedit/download.html).

This is observed using the TTF deliverables; when using the OTF deliverables, the macOS Font Book application reports critical validation issues as shown in the attached.