Yes, a few of the comments above surprised me, e.g. avoiding alerting or getting stressed about having alerted. I have a method which makes most of my alert times fairly accurate ….
… but if I’m late or early on summit (say, more than 30-40 minutes) I don’t worry about it because I know the majority of chasers will have realized that the timing for such an activity cannot be guaranteed.
If I choose to put back the activation time an hour or more, or I’m delayed setting off from home, I’ll edit the alert. Sometimes I have to cancel so will delete the alert often at short notice and feel absolutely no guilt about it. As from the lyrics of a John Lennon song "Life is what happens to you while you are busy making other plans”.
For chasers who feel an alert is a commitment and activators who avoid alerting for that reason, they should chill out – it’s a hobby.