I have a hatched style within my family which doesn’t export.
In 2017 I created the same style as a Sans Serif (but with less glyphs) and everything was fine:
Now, with the Serif, export works with disable subroutines but the file size grows to 2.8 MB … When “Disable Subroutines” is OFF, this style doesn’t export. I tried for 1:15 hours before I stopped the process.
If you have many paths, finding subroutines will take very long and can fail, that is why I would not recommend to use this kind of compression here. This is explained in detail in the Complex Paths tutorial.
What is the problem with an OTF at 2.8MB? If you have many paths, the file size is not surprising.