First I must say you have nice work done. That is the 6.5 hp, you have extra power!
About the oil you said your going to dial in, just was wondering how to figure.
I had an almost catastrophic failure with too little oil. But it came back from the brink.
Funny the pdf file for the engine with the exploded view actually has the engine of yours show sideways, just like you mounted it, unless you use some way to get the picture right side up. It was that and looking at the oil splasher fork and how in the oil sump it would actually be on your bike the way it is mounted. You do want enough oil for sure and it does look like a considerable amount extra.
See page 23 picture Oil sensor is also noted, Did you remove if it meant a parallel wire with kill switch stopping it from running tilted?
The breather on the engine since it has the tappets and valves way up high from the oil sump on that engine probably means extra oil does not get into the intake through the breather tube.
Be sure as the way your engine is tilted you have extra oil. I know you say you add extra oil to make sure the splasher fork at the bottom of the connecting rod clamp bolts gets into it long enough to splash oil as needed.
At one time I thought I had oil coming through the breather that sogged the airfilter starving the engine of air. Later I found it was intake valve tappet had 0 clearance. It was the gas from the carb bowl being sucked up during the compression stroke, the venturi effect shooting the gas spray the opposite way from the intake.
I have an Briggs 80202 0430 and I fit the engine tilted backward. Analyzing it and thought less oil to keep from having it get into the breather the way the old Briggs has it half way up the cylinder. It was OK with less oil, but the access to adding and removing old oil was difficult how it was mounted. I waited too long and on very hot day it was sized. Somehow I got the thing to work fine again by removing just the head and putting oil all around and trying to free up. Works fine again, wewwww!
Your Predator 212 engine and my old Briggs 3 hp don't have oil pumps, so unless they do there is no oil seal to blow out like on auto engines.
I got a replacement engine just in case I needed it, but it has a stubby 3/4 inch diameter crankshaft. I may just use it or sell it as the edger it can still be, but I can't find a way to figure the compatibility from old engine parts that maybe I can get cheap. Something about the journals, endplay.... I don't see enough info on Ebay to tell.