Buddy has a 461 he bought new pretty much when they came out that's been run at 50:1 it's whole life... thousands of hours on it as he runs a removal business. No issues. That's plenty of service life. Several lifetimes for average cutters.
Also, I have 250k miles on my Toyota Corolla...same transmission fluid...Pretty sure I'll get 300k+. Oil changed at manufacturers recommended 10k miles with 0W-20 which is like water. Not a single drive train failure. Again...perfectly acceptable service life. I think you ask anyone if 300k miles is a solid life out of a $23k vehicle, they'll say yeah.
All anecdotal evidence and obviously means nothing to you...but if 50:1 is good enough for thousands of hours of commercial work, it's plenty good enough for me. If it was blowing up saws or reducing service life significantly, we would be hearing about it a lot more than we are. IMO.
Hey whatever works for ya. Murphy often sits on my shoulder just waiting to hit me on the head. When it is my equipment and wallet on the line I will go the extra mile and spend the very few pennies it costs to make sure the lube and oil changes are taken care of to my liking. All manufacturers love to sell new stuff, be it parts or product. I have seen first hand what can happen the when the lubrication aspect is not up to snuff.