Almost every player plays the same shit at every tempo... so if you’re significantly slowing everything down. Just find a slower song. They probably played the same licks cleaner slow anyway. By the time you’ve picked a lick out note by note 2 or 3 time, when you hear it fast you’ll just know what it is without having to play it. For instance: Bobby Hicks ends almost all of his kick-offs and breaks with this lick at the top followed by a blues riff to fill the extra measure. Listen to Bluegrass Album Band. So learn something slow and diligently practice till you can play it fast and you’ll never have to transcribe anything fast. You’ll just recognize the lick and insert it!