Depending on how your engine has been "full flowed", the engine's oil pump puts full pressure into the output side when started up. If the outside temperature is under 30F/0C and the oil is very thick because of the cold, that oil pressure could be as high as 300 psi - enough to either distort your oil filter or detonate it.
Some outfits (Gene Berg comes to mind) offer a full-flow oil pump cover with a pressure relief valve in it that limits the output pressure to 125 psi. That's a very good idea, usually, especially on an engine that can output that amount of pressure into the external oil filter/cooler system.
I have used AN fittings on all of my full flow oil lines simply because I never want them to leak, let alone blow off from high pressure. While I'm vaguely familiar with "shark bite" hose connectors, I would never use either them or a clamp-style connection on a full flowed VW engine because of that high pressure potential explained above.
Just food for thought.