Hey hyspead,
yes of course. Masso does not support controlling VFDs by Modbus like the Buildbotics Controller does, but it controls them by the 10 V analog voltage for SPEED / digital input terminal for RUN/REV/STOP. This is supported by practically all VFDs. See Spindle VFD examples – Masso Documentation and Hitachi WJ200/Omron MX2 wiring to Masso GX12 6-pin connector.