Little late to the party, but: As Linux is the primary system in this use case and Windows is only used for "ROM maintenance" another option would be to use WSL2 to mount the formatted ext4 USB media directly if you run a recent Windows 10 (or moved to W11 already) and then access it via the Windows Explorer for example.

See https://learn.microsoft.com/en-us/windows/wsl/wsl2-mount-disk