FreeRTOS supports as much use of the MPU as you wish.
The use case for essentially 3rd-party modules that I've come across are basically all of the same form which is generic 1st party (trusted) code running 3rd party blobs for specific customers, examples being smart meters, Bluetooth devices, vending machines, etc.
The thing is... in most of these cases, the best approach is to sandbox purely the 3rd-party code, not your code (which hampers and slows development).
Although its nice in theory to also have your own subsystems protected from each other, in practice, the resource constraints prevent that being done well.
Putting tight controls just around the blobs on the other hand is a much easier thing to do.
The use case for essentially 3rd-party modules that I've come across are basically all of the same form which is generic 1st party (trusted) code running 3rd party blobs for specific customers, examples being smart meters, Bluetooth devices, vending machines, etc.
The thing is... in most of these cases, the best approach is to sandbox purely the 3rd-party code, not your code (which hampers and slows development). Although its nice in theory to also have your own subsystems protected from each other, in practice, the resource constraints prevent that being done well. Putting tight controls just around the blobs on the other hand is a much easier thing to do.