Isn't Schiit's implementation of the "buy better gear" LED something like what you're asking for? It's on Gumby and Yggy, not sure about other DACs from them. I believe it has something to do with not being able to reliably lock onto the clock from the source to let AdaptiClock do its thing.
To wit, I have an Yggy "B" bought recently and from my CD player via AES/EBU, it has never lit up. But from my PC, via 3M coax digital, it has lit up once that I recall, on a Redbook FLAC album. Doesn't surprise me at all, the sound card in the PC was just a cheapy to get a coax S/PDIF out which unfortunately isn't all that common and optical of that size run is going to be sketchy at best at 24/96 or above. But anywho, I think that's at least a rough approximation of what you're thinking about. It doesn't display any sort of "this is how far off you are" info, just a light on the front of the unit.