I played the drop-box audio.
Question: Is there a reason that it is 33 seconds of audio followed by 7 minutes and 12 seconds of silence?

If I understand correctly, there seems to be a misunderstanding about the 'commercial demo' and BIAB's version. The 'commercial' version is a pre-made audio file. It doesn't need BIAB to generate anything to listen to it. It's a pre-made audio recording. The BIAB demo version needs BIAB to generate and perform the music. Can you follow the difference? It's quite a significant difference.

What did PG Music support say about their demo and why you can't satisfactorily achieve the same result?

BIAB & RB2025 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones