I am fairly sure that BIAB includes the count-in when calculating the song length. I think that it has been requested many time to change this but it has never happened.
I excluded the count-in from the render, though that doesn't mean it still didn't include it.
When I first checked the time, VLC reported the file as a full 5 seconds longer than BiaB had reported on a 200bpm song. That sounds to me like probably both count-in and 4-bar ending.
My final 54s version reports as 52s.
Hmm ... looking at the Audi->Render dialog, I note:
Delay at start (seconds) 0
and
Delay at end (seconds) 2
OK, I need to check that ... maybe my 54s is including two seconds of silence and I may need to stretch it some more.
Well there's an interesting gotcha.