The man I learned from had been filling them for 50+ years. I have been pre-filling oil filters on every vehicle I have owned or worked on for the last 49 years. Not once was there ever a problem caused by this procedure. I know for sure better protection of Cams and lifters in the older engines. If you are working in an environment that causes concern about filling the filter, take care of it and get the job done. I don't like a lack of oil psi issue until the filter fills.
Nothing in that new jug of oil going to hurt anything., unless you put a piece of foil or plastic in there.
a paint filter works well as a pre-filter before the oil filter if need be. we were on a really windy job once and had a concern about the stuff flying in the air. so a paint filter works, but slowly. A clean t-shirt also works.
What is going to get poured into the filter other than clean oil?