Check language support tools

I'm aware of a few tools that check the language support in a font (OTMaster 370 Light — which I prefer because it also gives me a number — , Underware validator, etc... even Font Book info view), but they seem to all have a little different result of how many languages are actually supported/complete. I don't know that an exact hard figure can be had due to varying factors, but I'm wondering if others have found any of these tools to be most accurate? (Also already looked at this thread: https://typedrawers.com/discussion/comment/30880#Comment_30880)

Thanks.