Fonts can't be copyrighted. They didn't agree to any EULA. All they need to do is convert the font to some other format, and they are legal.
And BTW, this line is ridiculous: "It must be ensured that the Font Software cannot be fully or partially extracted from said documents".
It's possible to embed a subset of the characters, and that's what most require. But to prohibit even a subset? That means you can not use the fonts for any electronic documents whatsoever unless you convert them to bitmaps, which means they are almost useless for PDFs.
I personally would never buy a font with such a restriction unless all I made was print.
BTW, if you want to be legal, just download (pirate) the font file, and convert it to some other format. You never agreed to a EULA, and fonts can't be copyrighted (only the original file can be).
In theory they could complain about the original pirate act, but they would have zero evidence, and any subsequent usage is legal.