I happen to own a Precursor, and indeed used it for some experiments, but it's unfortunately limited by Xilinx Spartan-7 availability, which is one of the few FPGA's that have been reverse-engineered, and they probably don't make it anymore... Another one that has been RE'd is Lattice ECP5 but it's in the same category. I'm pretty sure you couldn't make 50 million devices like that. I know they've been looking into alternatives, but haven't caught up yet.

Their next one (https://baochip.com/) is going to be a SoC, piggy backed on another company's SoC. So not completely open source RTL, but enough to prove their technology on a larger scale. Bunnie's presentation of it is here: https://media.ccc.de/v/39c3-xous-a-pure-rust-rethink-of-the-... (25 minutes in)