STIHL owners have big hands, it's just the way it is.
The flippy caps are positive-locking, so they don't come loose and spill fuel, and in theory are easy and fast to remove/install.
The caps are still commonly discussed so I brought back a previously dead thread (because it's on topic).
In 2023 I had 4 geysers with saws made in 2023. What happens is the internal curve on the tank required by the flip-cap means the tank most always holds some fuel. At least some of it tends to be on the o-ring, and the positive pressure in the tank forces that fuel past the o-ring when opening the cap, which is a very quick-release 1/4 turn. Even on tanks without flip-caps the internal cap configuration causes the geyser problem (KM-130 powerhead). Regardless of the tank being "empty," the unit in a position so the cap is completely "up" and away from the fuel, and opening the cap slowly, I still got sprayed.
STIHL's solution is to let the saw cool 15 minutes before opening the fuel tank, which is fine if taking the time to eat, drink, sharpen the chain, and get a five-minute nap.
I happen to like the caps (mostly), though not the geyser issue; I put a rag over the fuel cap before opening (oil isn't an issue), so yeah, there's still an issue, though I remember that being the case with the 015 from 1970 and the similar insert-the-cap design.
Here's the one-way STIHL tank vent:
View attachment 1161189
From the top down, disassembled:
View attachment 1161188
From the bottom up, disassembled:
View attachment 1161190
STIHL 015:
View attachment 1161192