Re: 100:1 Mix
I've been using Opti @ 100:1 for break in and thereafter on my engines for a long time. Never had any issues with rings not seating. Never had a catastrophic failure, or any other engine issues. But that's just me.
Oil preference is like most other things. You need to do what works for you and let others do the same.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"