What I find interesting is that RP2350 is designed as "one or the other", no way to use ARM and RISC-V concurrently, and has fuses that can kill ARM M33 cores outright.
Makes me wonder if an "ARM cores fused off, RISC-V only, no ARM fees" SKU is possible.
You can choose Arm in one pair and RISC-V in the other pair if you want.
Several of the peripherals in the RP2350 are also ARM IP.