There is a growing movement in Bitcoin surrounding BitVM: https://bitvm.org/bitvm.pdf - which enables off-chain computation and bigger expressability of Bitcoin Script, their VM.
As part of an earlier hackathon project, some of us got a Cartesi RV64I circuit working as a binary circuit.
BitVM has now moved on to be more like a small on-chain VM with basic opcodes ( rv32i-to-bitvm/bitvm.ts at main · zippiehq/rv32i-to-bitvm · GitHub ) that is very RISC-V like, which uses bisection and merkleization of state using blake3 as hash function.
As part of a Xmas project, we additionally developed GitHub - zippiehq/rv32i-to-bitvm that converts/transpiles RV32I ELF binaries to BitVM programs.
It is not impossible that we could get the Cartesi RV64GC emulator building to RV32I like we did for Cartesi on RiscZero/ZK and “page in” pages within a 4GB memory space.
And have the Cartesi Machine as primary entry point for many new innovations on Bitcoin - which could be a very interesting positioning for Cartesi.
A possibility could also be RFPs around Cartesi+BitVM.