Windows Insider Preview build 17074 was released today to people in the Windows Insider program -- announced in the Windows Insider Program blog
. Among the many new features called out is that Microsoft Edge now supports the CSS extensions for variable fonts.
Also mentioned is that Windows now fully supports CFF2-flavoured OpenType fonts. This was supported in the Windows 10 Fall Creators Update in DirectWrite, but not in GDI, for which reason it wasn't impossible to install CFF2 fonts. But that is now supported in the WIP build 17074 or later.