One comment I picked up multiple times while talking/reading about webfonts, is that people are weary about creating WOFF and WOFF2 fonts because it adds so much work. These fonts need to be prepared, tested and validated, will introduce extra risk of broken fonts and cause more support questions. I also get the impression that local tooling, or on-the-fly font generation on a remote server, isn't to be trusted or complicated in usage.
I was wondering if there are any test suites or validation tools that people use now that could be improved, or what the requirements would be such a tool if it doesn't exist for your specific situation. Or examples of how current (command line) tools fudge up things, and how they should be improved.