I have generalized this as well, because time and again people get upset about all sorts of things, they have read something about some DIN and immediately start complaining even though they have no idea how the construction works and where the rules for execution are, I no longer build for others, only for myself.....
Again on the topic of thinking. Window sills are cut off and reinstalled, but not as agreed with 16 cm visible with 2.5 cm overhang, but with 18 cm and just under 4 cm overhang. And slowly I feel like I should start drinking.