I have an application that requires Bluetooth and either Wi-Fi, Cellular North America or Cellular Europe/World.
I would like to design a single "main" board that can handle all of these options. If the Photon 2 was available in the B SoM form factor this would be easier.
Will Particle make this or do I have to make my own B SoM with a P2?
It's not hard to put a P2 on an M.2 SoM form-factor board. I did it and it works, though there are GPIO mapping issues because of the different between pins and ports and the P2 and nRF52 M.2 SoM. It's unlikely that Particle will produce this, and I can't share my design files because there are some proprietary bits in it.
However, there will likely be a different solution for cellular vs. Wi-Fi from Particle in the future. It will be in the M.2 SoM form-factor, which is what we recommend for the best compatibility going forward.