For the moment, the BB transmits by SYSEX the Time Signature of the (first part of the) loaded song to MidiOut only when stopped.
But it does not transmit the time signature while playing.
(see BB no time signature sent to MIDI OUT while playing?)
We are missing some information here, because the time signature can change from one part to another.
I can understand that SYSEX are not easy to handle by the BB, especially while playing. So why not sending the Time signature using a simple CC ? Like with the CC102 that transmits the part number at each part change ?
At every measure, you could transmit a CC103 with a value describing the signature of the current part on one single byte (0-127) : 4 bits for signature nominator (1-2-3-4-5-6-7-8-9…), and 3 bits for the power of the denominator (2^1, 2^2, 2^3, 2^4, 2^5). Ex : 4/4 = 0 0100 010 =0x22 , 7/2 = 0 0111 001 = 0x39, 5/8 = 0 0101 011 =0x2B, etc…
And it could also be an easy way to count bars/measures, which is hard to do now (unless counting MIDI clocks)
It could be very useful for those who develops MIDI interfaces. 
Thanks for your help.
