The MIDI beat clock can't be sent as a single fixed value. If you read up on it, you will see that: "Clock events are sent at a rate of 24 pulses per quarter note". So MobileSheets has to generate a significant number of MIDI messages in a very short span of time to drive faster tempos. If your device can't handle this, and falls behind on the timing, the tempo on the receiving device wil be incorrect. This can be especially noticeable over bluetooth, as bluetooth is not a particularly reliable protocol to use for high-speed messaging. That's why USB and wifi generally work better for things like this. To be clear, this is generally a hardware issue, not a software issue, especially when it comes to the timing with bluetooth. This is also why it's better to use a control change message with the BeatBuddy to drive the tempo, so that it's exactly what you want without any variation. If you find that MobileSheets is not handling the bluetooth messaging for the tempo as well as you would like, but you have another application on your device that does handle the messaging better, and supports virtual ports, you could send the message out of MobileSheets using a virtual MIDI port (with an application like loopMIDI), and then that other application can be the one communicating with the BeatBuddy. So check to see if another application on your device can use bluetooth to accurately drive the tempo on the BeatBuddy.
Mike
Mike