Can't deceide between 2 down-convert options?

I have a UHD project which I need to down-convert to 1080p for local commercial insertion.   I tried 2 separate methods:

1) Dragged the UHD sequence into a 1080p project, exported as same-as-source (DNxHR) and encoded to broadcaster's specs in Squeeze.

2) Exported a same-as-source and down-converted to 1080p specs directly in Squeeze.

For the life of me, I can see any difference in quality.   But I'm using a computer monitor, not an expensive calibrated broadcast monitor.   I'm hoping someone who works with high-end calibrated equipment can tell me if one method is better than the other...or maybe there is no discernable difference?