Yes, you will see "whole" feathers dropping and pin feathers starting to emerge.So if the feathers are being dropped as complete, undamaged feathers, without any blood/veins, molting is likely (but not definitely, of course) the cause? Hearing your thoughts always helps me so much.
Edited to add: As you know, here in NC, our Temps have been all over the place, but our days are long. I'm not sure what else could be causing it but I certainly don't want to dismiss it if you don't feel like I should.