Can I use @font-face in RH2019 New UI?

We have custom fonts we want to include in our on-line help. So far to no avail.

I have woff and woff2 fonts, copied into the HTML5 skin folder. But the fallback font is used anyway.

To be clear: this is NOT about the title and TOC font of the skin itself; that will be phase 2. Just the topic body font, which I can regulate with my own CSS without any advanced hacks.

My fallback body font is wingdings just to be sure which font I'm seeing, and sure enough, the output looks like a binary file 🙂 So the font-face isn't working. I tried copying the woff files from the output's skin folder to the output's root folder, but that didn't help either.

Did someone successfully use custom fonts with @11220649-face in RH2019 new, HTML5 (azure)?