Damn shame.
Been "there" and it hurts...
Failure analysis can be very challenging.

Look VERY carefully at the head gasket.  Take a mic to the areas around that cylinder to check for clamp load and look for deformation around the bore compared to the other openings.  Check piston to see if it clamped the second ring tight.  I have had a head gasket do some considerable damage in the past.  If it leaks coolant it can cause the cylinder wall to split since water does not compress.  Starts a daisy chain of failures.

I actively avoid Aviad stuff when possible.  The Cobra pans seem OK as long as you don't mind redrilling half the mounting holes.  I have a Cleveland pan that was so far off square (1/8" plus) that you could see it from across the room.  Did not fit the car by over an inch. Called, send pictures, emailed them, and they told me it was the car and that I was wrong.  Fixed it with a welder.

We will use valley trays on flat tappet stuff if we remember to put it in.  By the time you clearance one for roller lifters it ends up looking like a lace curtain - not worth the effort.

Rocker trays get installed if they fit.  Since they won't fit on many aftermarket roller rocker systems - they also get left out most often.

I install windage trays fairly often.  The add exactly nothing on the dyno, but everybody uses them - so they must do something .  Probably helps with oil spray control hitting the sump.

I might have installed three slingers in 20 years...

There were several times this year (and last) when I had TFS heads and Summit had zero.  I think I sold 10-12 pair earlier this year when Summit was showing a 2-3 month lead time.   Seems counterintuitive but it’s been like that several times.

That is likely because of inventory and demand profiles.  As an example - vendor "A" makes 75 of something that is is high demand.  Motor State might get ten, a few smaller warehouses might get five each of the same item, and Summit might get fifty of them.  But, because of their size and need to fulfill backorders, Summit might run out way earlier while parts languish in inventory at a small warehouse.  Inventory and supply chain stuff was a big piece of my life for many years....sometimes very counterintuitive.

I've done that on dyno. 
Many years ago, when testing on a very, very early set of BT heads - before the T&D rockers were available. 
Pretty serious solid roller.
Broke shafts on both sides at around 6500 RPM or so...
Made a pretty good mess...

Most of the OEM carbs were rated on Holley's orifice box, and rounded to the nearest "5" cfm number.  Some of these were later converted to aftermarket carbs and the rat wings got tweaked as they changed boosters and such.  Somewhere here - buried in a box of old paperwork - I have a photocopy of many pages of the original hand written Holley part number assignment book.

Many (not quite all...) of the aftermarket carbs were rounded to the nearest "50" cfm number for marketing simplicity ie 700, 750, 800, 850 etc.

Later performance aftermarket offerings were rated by some arbitrary fantasy process as Holley reacted to the marketing pressures of the various carb modification places, and cannot be compared to older products other than by using Venturi bore, throttle plate, and booster data as you are doing.

Lots of really unrelated questions and answers have been posted here already.  Many of them are both important and correct.  But most of them are not going to cause - or fix the problem.  It's a material, dimensional, or finish problem causing rapid wear.  You already said you've tried multiple adjusters from several manufacturers.  It simply must be the pushrods or the rockers - or possibly (unlikely) the oil you are using.

Even with no oil up through the pushrod you're going to get enough splash to do the job as long as it's showing signs of adequate "top end" oil under the valve covers.  Unless the piss hole in the rocker is not aimed at the pushrod cup - or if it is not drilled at all.  The wrong lifter potential thing is 100% correct - but is not likely to be this particular issue.  Some pushrods have a full round looking cup that - if the diameter is too snug - might close themselves off from spray only oiling.  Others have a cone shaped upper that would allow splash to reside in them no matter how accurate the fit to the adjuster is.

Few - if any - folks keep them in inventory anymore.
Many key components are on perpetual backorder - with backorders orders piling up then a big "load" showing up, leading to a jam up as we try to assemble and balance.

As it stand "today" I have cast cranks and steel cranks.
That was not true two weeks ago.
Might not be true two weeks from now.

Should be able to get rods right now.
Pistons are an "order and pray" deal - depending on bore, compression, and phase of the moon...

I own the balancer - so that's not a problem, but manpower is.  See sentence #2 above.