You're over thinking it.  Just put the sensor in an inch or two forward of the point where it goes into the single tube/muffler area.  Get it as high as you can before hitting the footbox etc - just don't point it down to the ground (lowest spot would be vulnerable to removal by speed bumps...).  All the instruction want them "up to avoid moisture contamination and for longevity - but you really don't care if you need to buy another one in 30,000 miles.  If you're running EFI with it you obviously need it always installed.  But if it's for data gathering, you can put the bung pointing outside the car and plug it during normal use after tuning.  I have seem OEM test cars running around Detroit with tons of wires and boxes flapping around in the breeze...  No real car guy is ever going to object to the visuals of an O2 bung/plug - it gives you something to talk about for those that don't understand.

It's the amount of oil.   No wonder the lifters were clacking.

If it's a Canton T-sump oil pan, regardless if it's the higher end road race pan or not, the *system capacity* is 8 quarts.  That means 7 quarts in the pan, 1 in the oil filter.

You're still running too low of oil.

x2!

Good luck and enjoy the time ahead JDC. 
It's been an absolute pleasure meeting with, competing with, and working with you over the years.

Congrats on a good weekend

When doing EMC development I would often try different cams and, with the belt drive, make cam timing changes for each looking for improvements.  Usually the gains at one end of the curve were offset by losses somewhere else - and they were incremental.

I know of at least a couple BT high riser packages that went over a thousand - the Kuntz engine and the one Thor worked on for Gonia. 
Both of those are a long time ago now, and I am certain that others have gone further - but they are not promoting their results.
I also hold the billet heads to a different standard.

Rod bearing failures are always a treat to get to the bottom of because the failure mode is so rapid and destructive, rarely is there any good evidence left behind to help determine what the problem was or the root cause.  Some of the failure modes that I have seen analyzing warranty engines at work are due to the following.

1.  Contaminated / Dirty / Old / Overheated Oil.  Oil with coolant, fuel, dirt, etc can take out rod bearings quite quickly.  Navistar, Ford (6.OH-No!), and CAT engines from the 2000's and 20-teens that used EGR extensively to meet emissions are particularly prone to this.  EGR cooler develops an internal coolant leak, and all the sudden your engine is trying to lubricate with the green stuff.  I have also seen a bunch of rod bearing failures in air cooled engines due to oil overheating.  When I was at a small engine manufacturer, the life span of the rod bearing was measured in minutes once the oil hit 350 deg. F.

2.  Machining Quality.  Everything from surface finish, journal roundness, corner radius all can affect the lifespan of the rod bearing, and it doesn't take much of a deviation or miss to shorten the life span from 100,000's of miles to 100's of miles.

3.  Engine (casting) Contamination - See recent Toyota Tundra recall

4.  Crankshaft design / flex.  If the crank flexes more than intended or designed, bearing failure can result.  Typically this is more of a main bearing related problem, but it can lead to rod bearing damage as well.  PACCAR 13L engines are known to experience more crank flex than intended and this will lead to failed bearings.

5.  Rod Bolt Quality.  About 3 years ago, we started seeing a dramatic rise in rod bearing failures on Navistar I-Series reman engines.  Turned out, the rod bolt manufacturer (Navistar chosen and vetted supplier) had changed their process and the bolts were softer and did not have the designed tensile strength.  Bolts would stretch and lose clamp load on the cap, and the bearing would spin.  We discovered the problem by doing an extensive statistical study on our DC tool data (torque and angle) from assembly.  The failure rate was only 3 to 5% of engines, so it was difficult to catch, but there was a statistical change in the data.  The bolts were close to being correct (a measured sample would often meet the engineering print and specs), and they would even torque, yield, and stretch properly during assembly, but would fail within 10,000 miles.  We went down a number of rabbit holes before we figured out the root cause on this one.  Navistar ended up recalling all the rod bolts at their dealers and assembly facilities.

6.  Bearing Material or Quality.  Doesn't take much of a change at the supplier to cause problems in the engine.

This would be a good "guess" - the bearing is the "victim" of something else in the system.  Could be damn near anything.  Given the level of electronic management in a new engine package, it could even be something in the software that controls timing and fuel.  A bearing (or rod etc.) design that just meets or barely exceeds design needs won't have enough "headroom" to handle any unexpected loads.