CC 111 pauses, and then on a second CC 111 unpauses. The STOP settings can be configured to interact with the pause. As you found, the manual does not address the START command in this context.
I think there are presumptions made about how downstream midi gear will work. You could have the option of pausing the BB and still have your looper/echo effects continue in Beat with no drums. That seems like a good idea. When you unpause the BB, you still should be in time. Or, the BB can be set to stop the downstream gear on a pause, but then does it restart it? That’s going to depend on how the gear reacts to the CC 111. Does the downstream gear have a setting that allows pause on CC 111 and then resume on receiving a signal or 2nd CC 111. It is going to be gear dependent.
When we create midi chains of several devices, we introduce this complexity. That’s why channels were created, and why device numbers can get used by some devices. It’s why i’ve Used splitters and mergers sometimes to deal with these issues. Controlling without the ability to send multiple channel dependent signals, as you could with a DAW, gets difficult. It’s one more reason why we need a proper midi implementation chart for the BB.
All the above is just to explain that I don’t know for sure if a START gets sent. My guess is that it does not, as the CC 111 probably was assumed to be sufficient.