I don’t think the developer even thinks this will ever work. To begin with - this means that both parties must register their event on the service when making

I don’t think the developer even thinks this will ever work. To begin with - this means that both parties must register their event on the service when making the original plan. (How else would you later manage what to bail on and who that affects) Can you imagine anyone actually doing that? If you are someone who makes such flaky plans constantly, you aren’t also someone who will think ahead like this. To be honest reading the comments that treat this as something other than an obvious dead end is scary.