Is there a functional difference between Platformio's "framework-arduinoadafruitnrf52" firmware and arduino's official firmware

7

Which core is being used depends on the used board = .... Technically speaking, when you look at the available boards, there will be some which have a "bsp": {"name": "adafruit"} (–> Adafruit nRF52) or not. The builder script also showcases this.

So e.g.,

is a board which will use the Adafruit core, while

will use nRF5.