The water's hot enough everywhere else (this bathroom's sinks after the aforementioned delay, other bathroom, kitchen). The heater's set to ~130 deg F, which iirc is the upper limit of what's recommended and considerably above the ideal shower temp.
It really seems to be the dishwasher running that makes the difference. I rarely use the shower in question, but my wife does every evening, and it apparently doesn't help if I've done all the rinsing/hand-washing and loading of the dishwasher but not actually hit start. I don't understand the mechanism, but I believe her. I'm not sure if the dishwasher draws from the hot or cold tap.
It really seems to be the dishwasher running that makes the difference. I rarely use the shower in question, but my wife does every evening, and it apparently doesn't help if I've done all the rinsing/hand-washing and loading of the dishwasher but not actually hit start. I don't understand the mechanism, but I believe her. I'm not sure if the dishwasher draws from the hot or cold tap.