[CedarZ4]

Haven't done it myself but having been very interested in it, from my reading various forums, coding is like you said, only to adjust the front/rear bias.

In fact, many people on this very forum have done the M-Performance upgrade from the E9x without coding and there hasn't been any reported issues that I know of.

Edit: Related to front/rear bias, it seems that it specifically adjusts the ECU for the DSC. This was explicitly written by BMW for the F30 M Performance brakes as the reason for coding, so I'd imagine it would be the same for the E9x ones.