Hi NathanC:
Thank you very much for your reply. Being still relatively new to Affinity products, I had taken notice of the DPI notice that appears when I import a vector pdf document but haven't quite wrapped my head around how a vector has a set DPI since I always think of them of being infinitely scalable. I guess it comes down to how large the components are when they import and show on screen. With this in mind, it makes perfect sense that any mismatch of DPI settings between the asset and the document it's being added to could lead to a reset of line width. It's beginning to make sense, since I am adding the stamp to documents that no doubt vary in dimensional settings, resulting in what I perceived to be a "random" and unpredictable behaviour upon dragging the asset on. As such, it seems to me that the solution will be for me to expand the appearance of the outlines so that their width is permanently baked-in to the assets. I will give that a try.
Cheers