All I have to say is that those of you who have not had any problems leaving E10 in your OPE over the winter (or summer) have been very, VERY lucky. For every person who claims to have done this and not had a problem, there 9 other people who have had problems doing this. For many years I made a good living off of people who habitually did this.
you mut know my neighbor. He buys a new generator every time we have a hurricane.. it either wont start or he blew a hole in the engine because he ran it out of oil...
anyway I don't know where you come up with your numbers, or if they are accurate but for most of my adult life my SOP with all small engines is to fill them with gas, use them , then drain the gas back into the can and run the small engine out of fuel... I can't do this with my lawn tractor mower but I rarely put gas in it until it is low. ( I do live in Florida so it never sits for 6 months at a time of I would simply run it out of gas in autumn)
I dont know if I absolutely need to follow the routine I use, but I do know I don't have small engine problems for fuel related issues.