Take a look at the following code section. I think this would prohibit the use of an MCP on the line side of a VFD.
I don't recall MCPs being limited to use in a listed starter assembly.
430.52(C)(3) Instantaneous Trip Circuit Breaker An instantaneous trip circuit breaker shall be used only if adjustable and if part of a listed combination motor controller having coordinated motor overload and short-circuit and ground-fault protection in each conductor, and the setting is adjusted to no more than the value specified in Table 430.52.
"It is the first responsibility of every citizen to question authority." B Franklin