No desire to walk into a buzz saw here....but i also have a BP 302. The instructions clearly discuss priming the engine before first crank. I too thought, geez, they ran this on a dyno, seems it is no different than my car sitting a month while I'm on vacation. But the point is actually more simple...your motor is still under warranty. Follow their directions. Whether it actually helps or not is beside the point. And although this has been a terrible thing you have gone through, I am very happy to hear you have a newly built motor sitting in your garage. So, fact: they did stand by their warranty even though it caused some gnashing of teeth...you have a fresh motor. Prime it as they suggest, run it 500 miles, change oil, enjoy. That's what i did and so far so good.
And for the record
@Wallajw , I see you are new to this forum.
@jamesroney has forgotten more about engineering cars, parts, builds, engines, drive trains, etc. than most have ever known in a lifetime. Your comment regarding AI was not accurate and if you knew James, you would know that he is brilliant, needs no help with words (big or small) and if I were building a truck where every part needed to be machined from raw steel, there is one person who would be on that team...yep, James. Not sure your back ground, but please know that James, (although a bit direct and sometimes abrasive

is extremely qualified and has zero need for AI...in fact I think Chat GPT asks him questions.

So, we accept his commentary with a smile...and a notepad.