Hi Paul. I'm finding that it might be useful when I encounter text glitches that occur (seemingly with essential properties or in my case font by expression) when the kerning is defaulted to optical. As you look into the future being able to toggle optical vs metric might solve this problem for users, at least selfishly for me. I don't know of another way or tool that would have this feature other than yours, potentially. Thank you!
Hi Ben, the next major version of TextEdit (coming soon) will support setting kerning to Metrics / Optical. If you'd like to open a support ticket so we can exchange more information, I'd be happy to look into the exact issue you're having and ensure the new version will help solve it.