All true, but the radio chip [1] has two on-board ARM cores (an M3 for Wi-Fi and an M4 for BT) each with separate ROMs. So I would assume the library just interfaces with the chip and tells it what to do, not implement low-level radio protocols and so on. Weird that such a library is closed source, on the other hand. Annoying. :(
Edit: forgot to include the link to the radio chip.
Edit: forgot to include the link to the radio chip.
[1]: https://www.infineon.com/cms/en/product/wireless-connectivit...