In the spirit of the OP's point about tiny details, I can offer you two reasons why setting DST matters: (1) I want my cats to be fed just before I go to sleep

In the spirit of the OP's point about tiny details, I can offer you two reasons why setting DST matters: (1) I want my cats to be fed just before I go to sleep so the cats have the maximal period of full belly when I go to bed. I go to bed at 11:00 pm. Keep in mind that I observe DST changes for myself. But if I never adjust the feeder for standard/daylight time, then either the cats will be hungry until the midnight feeding or they'll be fed an hour early at 10:00 pm. In either case, they are more likely to wake me up for food during the night. (2) The cat feeder is in my bedroom and since I have it set to feed the cats just before bedtime, I don't want it making noise an hour after I fall asleep. That's what would happen when I've switched to daylight time but the feeder hasn't. The point is that there can be legitimate reasons why you'd care about a DST adjustment even if your cats don't.