They were delayed in the mail and I just got them this morning. No hyperflashing, and they are BRIGHT. I tested the radio in the AM band and didn't hear any difference with any of the lights on or off. I don't get very good reception on any AM stations to begin with, so your mileage may vary.
@lovell88 no hyperflashing with LED turn signals all around, including the mirrors.
Here's my current lighting setup:
Front switchback turn signals (3157):
https://www.amazon.com/gp/product/B08XBN8T38
Low beam headlights:
https://www.amazon.com/dp/B07C1LTQ92
Headlight dust covers (83mm):
https://www.amazon.com/dp/B08PTVMQKH
Front side markers, high beams and fog lights are still stock
Mirror turn signals:
https://whoosh-motorsports.myshopif...signal-dynamic-led-lights-2014-2019-fiesta-st
Rear turn signals (3157):
https://www.amazon.com/dp/B08Z34QY4X
Brake lights:
https://www.amazon.com/dp/B06XVT9D1W
Reverse lights:
https://www.amazon.com/dp/B074RFY776
Everything works as expected on my otherwise stock 2019 North American Fiesta ST.