Yeah the oil mix ratio thing has been beat and beat and beat on here, I say do what you feel confident with and what has proven to work for you.
I dont use "breakin" mixes since I think its useless really, if an engine is right you tune it for what you plan to use, take it easy for maybe the first 15-20 minutes of run time and then just run it like you plan to run it, if it holds up you had a good engines, if it doesn't it was gonna fail anyway.
This doesn't mean I think everyone should do it my way, it works for me on these little 2 smokers just the same as it always has on all the other engines I've built over the years.
Where so many mess up and burn up these engines is by using to much oil in the mix and having a lean run condition, more oil, less fuel, less fuel leaner run, leaner run high heat in the cylinder.... proper jetting with whatever you run is the key to the engine lasting if its all good mechanically.
Bad bearings are gonna give it up with a 16:1 mix just as well as a 40:1 mix
I like my Opti2 at 100:1 for a moderate build, you can pull one of my engines down and they are very oily inside, I do however add Maxima 927 Castor to my mix for my higher rpm running engines and they're tuned for the e,tra oil and the mix is around 50:1.
again, run what you fell good with and what has proven to work for you is how I see it.
