Although not strictly necessary there is a tool for reading and writing U-boot environmental variables from within the Linux OS ( https://github.com/sbabic/libubootenv or “sudo apt install libubootenv-tool” for a binary package from 2021-12-14 ). But obviously this carries the risk of breaking your U-boot environment and if used too often it could rapidly consume the limited write lifetime of the 16 MiB flash chip which is soldered to the board.
It may need to be patched for the VF2 board, or a customised /etc/fw_env.config file created specifically for a VF2 board. I have not tested it (no board yet).
EDIT: Might be best to ignore my above suggestion for now, I’ve submitted an issue on github for something I noticed when trying to workout the details of the boot process.