I guess I don't understand what you mean by impersonation at least in this context.. I think the disguise stat only comes into play with people that know there person you are impersonating..Say you have the minimal disguise skill and you put on a hat and say you are Mickey Mouse..I can assume you are lying but I can't prove it..There's no mechanic that I know of where I can rip your disguise off.
For example, if you impersonated me and went to another city I never been to your disguise score wouldn't matter. If you went to Fennec academy where people know me it might break assuming there is some time of dice rolling going on in the back ground. Plus VOIP would just mess the whole system up if people are cautious.
Here is something from the Dev journal
"Whenever you, or someone around you, assumes a fake identity there's a chance others will recognize it as a fake. The percentage chance that someone can see through your identity is based on the number of times you've encountered them before. The more times you've encountered someone, the easier it is to recognize the lie. If you're not wearing a disguise, it may only take a couple times interacting with someone before the fake identity is discovered. Putting on a disguise will help with your charade but even still, the more you interact with someone as multiple identities, the easier it will be for them to recognize the identities belong to the same character."