Please pardon the copy and pasteas I have gotten tired typing the whole thing out every time but this is my opinion.
First of all the oil needs to be readily available, convenient to obtain, and reasonably priced. I also like to use an oil that carries the name of a reputable manufacturer of reliable and durable AIR cooled engines but this is not a requirement as other oil producers have good quality oil. Some good examples are Penzoil for air cooled engines, Stihl, Echo, Redline, BeRay and there are others. Lawnboy is not one I would use based on what I have seen the oil do to an engine. I like to use synthetics because they tend to leave the engine a little cleaner inside, run cooler and have better lubricity. I use Stihl HP Ultra, there is no good reason to use a different oil for break in than what I plan to use long term in any engine we use for model aircraft. I do run a new engine on a stand for a couple tankfuls with a bit more oil, (32:1) just to get things going. I adjust the carb for optimum performance by the end of the first tank, I would NEVER fly a plane with the carb set at the "factory" settings. After the stand running is complete it goes on a plane, fueled with a 50:1 mix, adjusted again and flown. I won't mess with needles again until the engines tells me it's not happy, this is usually after a couple gallons and may happen again within a few more gallons. I check the plugs for color after about 5 or 6 gallons to make sure things on the inside look as well as they sound on the outside, small adjustment if warranted, and then I won't touch anything for probably a year unless the engine tells me it wants some attention but by this time it's very rare. If I make changes to the prop, exhaust, fuel/oil mix, baffling, etc. then I'll revisit the needles. Another important rule of thumb I live by that I forgot to mention is for mineral based oils I won't run any less oil than 40:1, for synthetics it's 50:1, NEVER less oil than 50:1.