I can play and improvise around the melody of the song regardless of the name of the scale that the notes are coming from (mostly root, b2, 3, 4, 5, b6, b7)... But I don't know, just out of curiosity, do you have any insight on this? The name "phrygian dominant" threw me for a loop.
'phrygian natural 3' would be fine. but a lot of people maybe don't know the word 'phrygian', in which case you'll have to spell out the numbers like that. and if they don't speak numbers then you'll have to just show them which notes to use and then you're good