Honestly, range as a comparison point doesn't really work as it's inconsistent as all hell.
But I mean, Cosmo was able to scan for Starlord in the negative zone whilst he was on Knowhere, which is at the collapsing edge of the universe, so that's pretty impressive scope. However he's not on the level of others in a ton of other telepathy feats, so scope is a pretty bad way to judge it.