Is there any possible to flash self bluetooth stack into the nordic series?

[desword]

As show in the title, suppose I have my own bluetooth stack implementation, Is there any possible to flash the bluetooth stack into the nordic series?

Or, another question: Is the nordic softdevice.hex support the low level development? Such as modifying the MAC layer of the Bluetooth?

[Keton]

If you port your code to the nRF series there's no reason why you couldn't do this. You can use nRF5x without softdevice having 100% control over all peripherals including radio. As for the other question I don't think so. Softdevice is provided as closed source software in form of binary blob so we cannot modify it and it abstracts away most of functionality below GAP.