Does something like this seem to you to be a reasonable rule of thumb, for helping handle scope insensitivity to low probabilities?
There's a roughly 30 to 35 out of a million chance that you will die on any given day; and so if I'm dealing with a probability of one in a million, then I 'should' spend 30 times as much time preparing for my imminent death within the next 24 hours as I do playing with the one-in-a-million shot. If it's not worth spending 30 seconds preparing for dying within the next day, then I should spend less than one second dealing with that one-in-a-million shot.
Relatedly, can you think of a way to improve it, such as to make it more memorable? Are there any pre-existing references - not just to micromorts, but to comparing them to other probabilities - which I've missed?
If you believed you had a very high probability of death soon, then that knocks one of the basic assumptions of this potential-rule-of-thumb out from under it, rendering it much less relevant for that particular situation...
... but as one potential answer for your question - how about taking the time to wrap up your conversations with loved ones in a way that you feel would be suitable as your potential last words with them?
You're right, I should rephrase. What are things you actually do or might do, at your current estimated probability of death within 24 hours, to prepare for death, that fit in 30 seconds daily?
For me the answer is: none. If that is your answer is well, then your rule of thumb is telling you to ignore entirely sufficiently improbable things, on the order of 30/1000000 est. probability or less. Was that your entire intention in proposing this rule?