Hello (and merry christmas)

I have my eyes on the Ergon BC2. Looks nice, comfy and robust.

However, sometimes I will wear it while I'm also wearing a POC Spine Protection Vest. Works fine with my Camelbak Mule - but since the Ergon is build up with a frame, I was wondering how it would fit together. Unfortunately I can't try on the Ergon pack, since I'm ordering online. (No dealers around here)

Can anyone clear this up?