I agree fully with the nice, soft break-in, plenty of oil changes and checking accessible bolts 4-5 times in first 1000 miles. And by checking bolts I dont mean cranking the snot out of them over and over until its a pile of heli-coils.
I believe the main factor in bedding rings comes down to the final hone given to the cylinder walls. Stones that are too aggressive leave one thing- deeper scratches. Those "scratches" need to be worn down to smooth by the rings rubbing on the cylinder walls. Obviously, the deeper the scratches the longer this takes, the more leakage you have past the rings for a longer period of time. If you think of hone marks like "mountains", the higher the mountain the more dirt you have to remove to flatten that mountain. That means more cast iron particles floating around somewhere in the motor, for a longer period of time.
I believe the angle of attack with a hone is a major deal also. Thinking of the barrels standing straight up and down as 90 degrees, you want 25-35 degrees on your hone marks. Honing motions done too fast, 60-70 degrees dont help you at all when you talk cylinder pressures and leakage. Angle is a consequence of the speed you move the hone in and out of the barrels. Slow, and steady with a fine hone, and remember you are honing, not boring. As soon as you have hone marks covering the entire inside surface, you are done. No need to do this for 30 minutes or whatever uncle stinky told you to do when you were just a kid with a go-cart.
I dont know about anyone else, but when we built motors to race with- motors that went literally wide open all the time, we built slop into them. If you would build a decent street motor with 1 to 1.5 thousandths clearance, we built with 2 to 2.5 thousandths. meaning we built them broke in and loose. We knew it was coming back apart soon anyway, why risk a seizure? Racing motors are generally not built to lost a large amount of miles- hence one of the reasons serious racing is a very expensive, time consuming hobby. In my experience, motors built for racing are built far different then motors built for longevity, but maybe that was just me.
I also know that most hobby guys dont build a motor and stick it straight into the car/bike and start it up immediately. Most sit for weeks, months, maybe even years before being called into service. I cringe when I see guys use engine oil to assemble a motor, especially if the motor will sit for some time. That shot of 40 weight will have long settled out by the time the engine is fired up. Basically a dry start. Now a days they make assembly lubes that will give you some protection for the first couple minutes until oil pressure hopefully reaches the critical areas. This stuff is thick like snot, and sticks around a while. Its cheap also, compared to a rebuild.
I also believe the idea of "cheap oil, and rev the snot out of it for X number of minutes with a bag of ice on the rocker box and a Voodoo queen standing by to administer magic", is a bad idea. This may have worked for someone, but that does not make it gospel. Its a motor, and an expensive one at that. Use good oil with the highest zinc content you can find, probably a break-in oil. Use pre-lube to assemble, more does not hurt anything its just a little waist full. Hone the cylinders correctly, lightly lube the cylinders but be sure to wipe out any excess, it will do nothing but foul the plugs and smoke. Make sure to either kick the bike over without fuel and no plugs until you have oiled it, or take it for a walk until you do. Treat it gently at first start while rough setting the carb, get the bike warm but not too hot. Change the oil either at 5 minutes of run or 2 miles of drive. I can hear it now "how waist full to throw out that oil", that oil is now full of pre-lube, a lot of the tiny particles of debris left in the motor from before the rebuild, bits of bearing, cast iron particles, and a bunch of other crap you really dont want circulating around in there. Get rid of it, fresh oil is a lot cheaper than a new timing side bush.
The tighter you built the motor, (and only you know how tight it actually is), the more often you should change the oil. All those new parts in there are mating together and breaking in together. In a perfect world the layer of oil between parts would keep them separate and you would never have any wear. But we all know thats not true, so wear is the removal of metal. And all that removal ends up in the oil. Dont get a new motor over hot, thats when things seize. Take it easy.
Dont over load a new motor, vary the revs but dont red line it. Dont go out on the freeway and drive 200 miles at exactly 60 mph, thats not helping.
I dont know why some people are so afraid to change the oil, and do it often. They will tell you with one breath they have $3000.00 dollars wrapped up in a new motor, and in the next complain that new oil cost $20.00 and they are not spending that kind of money.
Most of those motors we build are for longevity. We know they are expensive to rebuild, quality parts are not easy to find, and we just want to enjoy good running machines. Its the same in all motor vehicle hobbys, be it cars, boats, bikes, or even flying those model airplanes. I dont think I have to force a motor to break in inside of 20 minutes while risking a major malfunction while doing it, to enjoy this. I think I will take it easy, enjoy the 500 or so easy miles, save my heart some stress, and I will certainly change the oil often and use the best quality lubricant I can find.
These are just my beliefs and I certainly could be wrong, but it really is how I rebuild and break in a motor.
