Thanks for sharing it with us. I am facing the same issue, someone annoying me with a similar telegram username of mine. Even I have written a note in my profile, but I have received a couple of messages that imposter succeeds to scam. Although there is no fault for me, but I feel bad. I have also created a few warning threads as well to prevent that imposter.
No worries man! That's good to know. One possible solution could be sharing telegram only with the users privately instead of having it on the profile because it becomes easier to copy the telegram handle and create a similar one. I'm still brainstorming a better way to handle this.OP, are you saying it's the "Brainboss" part of the telegram handle that's making you think he's impersonating CryptopreneurBrainboss? I wouldn't have assumed someone with the handle @PedroBrainboss would be trying to impersonate CBB. I don't even know the significance of "Brainboss" is, though I'm curious.
Oh not just that, their username on telegram is also CryptopreneurBrainboss. They linked me to the original forum account of CryptopreneurBrainboss when asked who they are on the forum. They linked me to the real CryptopreneurBrainboss's forum account's trust page too. So clearly a case of impersonation. 
