I’m doing this as well without knowing it’s a thing that is done by others. I hate test cases, so I use Test Ideas. Test ideas are trigger words to jog my memory when I do exploratory testing.
These trigger words are written at the time I read the user stories or when I just remember something to be used in my testing.
So for example, I’d write the word ‘Time’ as a keyword. When I perform exploratory testing, I then use ‘Time’ to model the system I test. This allows me to think what ‘Time’ has to do with the system. This leads to checklists similar to what you mentioned. Like: 1. Validate cron jobs timings 2. Test timings of complex db queries. 3. Time zone differences between DB time zone and customer timezone. 4. Anything that has time stamps. 5. Time the end-user get their results. At the end, this sort of checklist may turn out to be a lean test case in the form of a check list as you described.