They also have the Prius Prime and Rav4 Prime models which have larger battery packs and charge ports compared to their standard hybrid variants. These models don't support DC fast charging and still operate like standard hybrids so having the larger charge network isn't as important.
I'm not sure if the existing Tesla level 2 "chargers" would work in this case but assuming they do it would offer more options.
The SoC and memory are separate dies with different manufacturing processes. In the case of M2 it was TSMC for the SoC and SK Hynix for the memory.
When it comes time to package them together, the SoC and memory are soldered to a interposer layer. So the only difference is which size memory chips they solder together for the different memory configurations available.