Interesting. So, if that’s really what happens under the hood, you should lose the compatibility with IE8 to 11. Can you test the support for those browsers with your site? Is it really broken?
You’ll find that often, woff2 is given to not suppert Edge 12-14, but that’s not true.
Are you going to ONLY use the woff format? (simple question). I think you can. Woff is supposed to cover almost all browsers. Woff2 is more limited, especially for old browsers. Most problematic with Woff2 is it doesn’t support Android KitKat and lower, which is more than 12% of android users (as of fall 2018), and IE lack of support, which is another more than 10%.
Woff2 has a better compression but not that much better. And it’s letting down 22% of users.