Dan, I think his issue is that when you enter a chord, everything that happens during performance does, by design and default, play "in the box." Can't add a pick-up unless it is a two-bar phrase (and then in the wrong bar...) because the program has to wait till it gets there.
And I will agree in a general way, but the workarounds let me write moire simplified forms of what I really want, and I can usually edit in my DAW to fix that. My problem (elsewhere) is with the shots and holds, but it is part of the same issue - the built-in limits of the concept. Music is simply more flexible than that.
Bottom line: I used to use iReal Pro for live performance backing tracks - still do for requests. While I will not get to be the next Joe Zawinul with BiaB, I will be WAY closer.
And certain styles, like OG's "Freddies," are the answer to a thirty-year quest for a non-drinking rhythm guitarist (OK, he needs his juice, but...)