Hi Dave, thanks for trying!
No, it is not that simple.
It is exponential latency. It is consistent within tracks exported from arranger. You do not feel it first 4 bars or so, than it is more and more evident. By bar 20 it is a chaos.

It is an uphill battle with developer of that arranger record audio of correct tempo. I am 99% sure it is not related to my hardware. I am left with current and future files from arranger and BIAB. I hoped that joining those two file sets would be a love from first sight, but it feels more and more like arranged marriage frown

Misha.