The problem with pre-filling filters is idiocracy. Sorry, many morons do a horrible job of removing the aluminum/plastic seal on jugs/bottles and that seal ends up in the filter, and on the wrong side of the filter. Pulled plenty of seals, funnel tips, and bottle caps/rings from under valve covers and expect the same inside filters. My favorite foolishness are destroyed engines caused by funnels breaking the PCV baffles/shields off under the valve/rocker cover. If you can't fill an engine correctly without problems, should you be filling your filter?
I prefill all my filters regardless of mounting location. On sideways or upside down filters, I can still pre-fill and soak the media without spilling a drop during installation. And, I prefill cartridges too.
So, if you are not a moron, then prefill your filter. If you are not capable of filling the filter without debris, maybe you shouldn't be doing your own oil changes. I mean, if you can't remove the plastic/aluminum seal, or the plastic cap/ring, off of a jug or bottle of oil, or use a funnel properly, stick with jippylube!
Funnel companies have 'vehicle specific' funnels now too. Oil bottling companies need to idiot proof oil bottle seals and cap rings.
I would also not recommend pre-filling a filer during a sand storm
That would be uncommon sense.
I don't care if you do or don't and if you think that its fine to do or not to do.
Btw, I won't start a new/rebuilt engine without priming the oil system too.
Maybe you don't trust these clowns masquerading as an engine company... but this is what they say:
The problem with these fancy funnels, in the hands of DIY clowns, is that many don't have a 'screen' to catch foolishness:
www.motivxtools.com
Even a Behrens, older than most members here, has a screen:
50 mesh brass screen of the 1 quart funnel makes automotive projects and oil changes a breeze. The galvanized funnel is made in the USA.
www.behrensmfg.com
And, what ever iffylube or indie shop should be using:
The Drum Pump Filtration System removes contaminates by filtering lubricants from 55-gallon drums when filling transfer containers used for top-offs.
www.tricocorp.com