Jim,
Theres are alot of people loving the cheap CB lightweight lifters. Have you considered using those with a cam of choice??
Since your engine is together with the fk45 and bugpacks I'd use 1/2 bottle of GM EOS and your choice of diesel (valvoline blue, Delo, Rotella, etc) this will easily go into the 1500ppm of zinc.
The thing about zinc is its the last barrier. Hopefully you dont get to that point. I would have liked to see what your lifters looked like after using Lubrimoly 5w40 (pao base). I guess the theory of synthetics is that it will provide better film so you dont get down to metal to metal. Sometimes I wonder if we simply get jaded by zinc PPM numbers. The oil base is a factor and the combination of the additives that go in it.
Oil is such a hot topic these days but you must look at a persons application too. I've used ELF 10w50 PAO and I think thats been a great oil for my 2332. I will tear down my motor when I "feel" fit so thats very frequent for my hotstreet engine. I use chevy valetrain so the lifterbores get beat on and my cam constantly gets stiff pressure knawing at the nose

So realistically I can confidentally get away with using Rotella T/valvolin premium blue with some GM EOS and save a bundle of money.
I'm currently using udo lifters (heavy version of tool steel) and I've beaten them brutally with an fk47 with wobbled lifter bores. I cant imagine how any other lifter would have taken that much abuse. I only ran 200+km's till the case was completely wobbled to hell.
Udo lifters new (early generation tool steel lifters)

"AFTER" picture with 200kms with chevy valvetrain with severely wobbled lifter bores. The lifter is PERFECT!!
I think most VW dual spring engines will eventually get less abuse since the valve springs get real soft in a short period of time. This reduces stress on the lifter bores and cam / lifter contact point. The spring pressure is the real killer and if your not floating the valves and using a lifter that doesn't typically pit (you know what brand) you'll be fine.
My view on lifters has changed completely after I saw how good my tool steel lifters look after malicious abuse. My 2 NOS set of schubeks wouldn't have lasted with that kind of abuse I gave to my udo tool steels.
I guess we can turn green and discuss oil but bottom line is if you have the right lifters any good quality oil with good dose of zinc it will have a good life. Reduce the spring pressure and your lifters/cam will love you even more.
The true test of wear (or lack of) is to use a dial indicator and check your valvelift on a regular basis.
That castrol PAO must be expensive. What alot of oil geeks are finding is that a good quality shell helix hyrocracked group 3 mineral oil are giving just as good numbers compared to a PAO synthetic base stock. So in other words who or what do you believe.
Thing about used oil analysis is you'll get a variety of different readings from similar engines. So many factors like dampers wearing/friction against the duals inner spring, differnt radius on a certain brand lifter and different taper on different brand camshafts, hone finish of the cylinders, type of rings used etc etc. Call me a man with blind faith but if you have consistant valvelift thats a piece of mind.
I was using some ghetto cheap riosolence brazilian lifters with my favourite CB2289 cam and chevy valvetrain. That combo lasted me 2 years till I decide to inspect inside the case. The lifters had no dish but they started to go concave marginally. I retired those lifters and cam but she lived well with my abuse.
All I say is use your favourite slippery stuff with GM EOS or favourite synthetic and if you have consistant valve lift your fine.