If Stihl had never changed the design of their caps we wouldn't be having this debate.
They changed to the flippy cap, and by and large it presents more problems over time than the screw cap ever did.
It took over five years for the screw cap on a training saw to get buggered, multiple users, heavy handed trainees...finally got a hole in it.
The flippy cap CAN have issues straight away, getting that extra twist in it before you get it seated, so you then have to get a hand full of oil to wind it back...or miss the fact and get a leg full of oil, or worse not get the gas cap seated properly...OUCH!!!
You have to make sure you don't overfill the oil tank with a flippy cap, 'cause it won't seat, or you think it did, them pop, glug off it comes just as you pick it up... with a screw cap you just wound it down and 'splooch', wipe up the oil and carry on.
I have a combi can that has a spot for a scrench between the oil and gas cans, so I'm never without one when filling the saws...so that issue is a non-starter.
So, I have a few more minor things to check when working, or make sure that the groundies check...minor things I've learned to deal with, but could well have done without...