Since both PPP2 or Plasma2350 have a SP/CE connector, enable WiFi in all cases.
Additionally enable PPP in all cases.
Finally, drop the non-PSRAM build. (TBC if it returns, since it's less RAM but faster.)
Pico 2 / Pico 2B: Change to match upstream RPI_PICO2
Pico Plus 2: Allocate 2MB to firmware
Tiny 2350: Allocate 2MB to firmware
Plasma 2350: Allocate 2MB to firmware