I own a number of rc helicopters and 2 planes, blheli firmware on brushless esc's will work fine with all receivers.
At first it confused the hell out of me too but I soon discovered it's how the esc process the information and it's all about response times.
Theres a tonne of different firmwares out there and they can be re flashed, this is great as because they are now so programmable, you can plug the things into a serial based USB adapter and set up all sorts of parameters on them through your pc like soft start, max throttle output, reverse or not, motor braking, the brushless timing, the list goes on and on
but the point is you can customise them to work in a way that suits your particular model with a few clicks of a mouse instead of the incredibly confusing beeps from the motor and transmitter stick programming,
trying to program the old way through the transmitter where you have to work out what all the bleeps mean and the actual process when the manual is in chinglish or even no manual at all is enough to raise anyone's blood pressure!
Pc programming with easy to use software like blheli suite is the way to go.