Would it be possible to remove the definitions of <font-format> and <font-tech> from CSS Conditional 5?

The spec says:

This level of the specification extends the <supports-feature> syntax

But it does not extend these subproductions. Worse: <font-format> is only a subset of what is defined in CSS Fonts.

These duplicate definitions must be specifically handled in w3c/webref, by defining an "authoritative source" for the production, which is not great.