There are now 10 messages for bike_profile with message_number=6 in Settings.fit. Each of these messages has a message_index field which contains the sub-field mask which contains what appears to be a valid index value.

bike_profile (6, type: 0, length: 81 bytes):
    name (0-16-STRING): "Bike 10"\n
    message_index (254-1-UINT16): selected=0,reserved=0,mask=9 (9)
    ...

It's unclear how one might reference a specific index of a single message_number.

Is this supported?