Hey Atroz,
on Omron MX2 / Hitachi WJ200 and some other VFDs for industry, you can additionally use their emergency circuit capability. These industry VFDs have ISO 13849-1 Safety Inputs with which you can put the VFD into an emergency stopped mode. This will prevent the spindle to run even if you press RUN ;).
Possibly you can use some of the programmable inputs of cheap chinese VFD to have the same functionality.
Usually such Safety Inputs are wired to an ISO 13849 Safety relay such as a Omron G9SE (an example wiring is shown here), but you can also enter the Safety mode whithout such a relay, just by connecting a switch to the VFD.