Though you should try your best to capture all to-do items on a single list, that doesn’t mean you can’t use other tools from time to time. For instance, anytime my wife says “remind me to do X at Y time,” I immediately, in front of her, say “Alexa, remind me to do X at Y time.” I’m trying to train her, but it hasn’t worked yet.
I also like what David Allen says in his book “Getting Things Done”: “Here’s a method I like to call ‘put it in front of the door.’” It’s hard to forget to take something with you when you trip over it on the way to your car. Before I could ask Alexa to remind me of something, if I thought of something while laying in bed at night that I needed to remember the next morning, I’d often pick up a shoe and throw it into the hall. My wife would inevitably and understandably ask what I was doing, and I’d explain that the shoe doesn’t belong in the hall, so when I get up and see it in the morning, I’m going to wonder why it’s there, and then I’ll remember whatever it was that I didn’t want to forget. Isn’t that better than thinking about it over and over again while trying unsuccessfully to fall asleep?