Some of the filming modes that are available in stock camera are not available in mcpro24fps. Why?
In short: the stock camera is an application written by the manufacturer of the device. It always has maximum access and opportunities. Third-party applications have access only to those functions that the manufacturer has opened for them.
More details: Access to these functions depends on the version of the API: Camera API (hal1) and Camera2 API (hal3). Some functions may only be available in one version of the API. This situation often happens with 60fps mode when it is available in the Camera API and is not available in the Camera2 API. Mcpro24fps supports only Camera2 API. Also, the 60fps mode is often only available in the automatic exposure mode. This is a hardware limitation that cannot be known in advance.