That reminds me a lot of the xmos xcore mcus with 8 cores. I am curious what kind of synchronization primitives have you added and why?
It's a good model for MCU stuff. There were people pushing Chip Gracey (Parallax) to use RISC-V instead of his custom ISA when he designed the P2 a few years ago, but he chose to do his own thing. Which has made compiler development difficult.
I'm assuming he probably has some sort of roundrobin shared memory access similar to what Chip did with "HUB Ram" on the P2.