I've successfully configured GNU Guix offloading on VisionFive2 board (RISC-V) to my main machine, to speed up the building process.
Used this part of the Guix manual during the configuration:
https://guix.gnu.org/manual/en/html_node/Daemon-Offload-Setup.html
It was non-obvious for me that for RISC-V "build-machine" the "systems" list should contain "riscv64-linux" string (instead of "riscv64-linux-gnu" as "guix build --list-targets" prints.)