But mum, look, if anything has happened you'll get a bloody phone call. With this system my not texting just primes you to worry more, despite the far higher likelihood that I forgot than that I'm dead.

Literally the best result is that you start worrying I'm not ok a few hours before finding out for certain that I'm not. So let's assume success, and agree that in case of failure you're going to have a very bad day anyway and this doesn't really help mitigate anything at all.

(this does not work)