I've been using chat apps "send to self" for this exact same workflow.. at work I just use Slack as it supports threads and basic formatting (e.g. render code blocks separately and clickable links). So every day has a few threads on different things I'm working on and I can just add notes on them as I go throughout the day. For my own projects I use a messenger app, which is not as nice because most messengers do not support threads. I was actually considering switching to an external text file for versioning purposes.. and being able to render code blocks would be nice, org mode looks like overkill though.
I like Slack-to-self for the reasons you list and also because I think of things to do whilst out walking the dog, sitting on the bog, or should be sleeping like a log (like now).
