I do think a mic captures more of the overall sounds that a string instrument makes which makes it a really valuable way to record one, though i dont have much experience with piezo pickups so I can’t personally compare.
Your setup sounds cool, do you have any stuff you’ve made that you could share so I could hear it?
I do really like Zoe Keating actually, I’ll have to check out Francesca Guccione that does sound really interesting.