A few notes from my perspective. First of all, the M&P engine does give some rights to the programmer to adjust things "under the hood" though not entirely. (Melee calcs is one of the ones I don't have much access to).
But, what I was going to say is this. I actually am not the only person working on M&P. Aside from Rich White who did REN years back, there are other M&P projects that are proceeding without my exalted presence

I can't really say who/what, but it's certainly the case.
Which actually does create some headaches, and I still have some lingering fear that when the next REN patch comes out, something there will be broken by updates from SYW. Whatever comes out next will have its own issues and perspectives. (For instance, this game engine also covers the era of caracole and mixed pike/shot units.)
I'm happy when John puts more things in areas I can work in directly like the pdt file, but I have little interest in actually coding the game. More importantly, I have little ability to do so. I've got a BA in History and a Masters of Divinity in my pocket, but my only programming classes were back in the 80's in BASIC and UCSD Pascal.