I'd like to see a RCT that compared two time-restricted eating groups: 7am to 3pm, and noon to 8pm. Which would have the larger benefit over a control group?
Also, it would be good to simultaneously (somehow) check if the results depend on one's genetic or cultural bias towards eating in the morning or evening.
It most definitely is highly personal, like most weight management advice seems to be.
The only immutable truth is that calorie deficit will make you lose weight.
BUT different people find different methods of calorie deficit easier to handle mentally and/or physically.[1]
I can easily go even 20 hours without food maybe only sipping on some water or tea, my grandmother is the same. She can just have a big meal once per day and go about her day (and night) just fine.
My partner on the other hand needs to eat every 3-4 hours or they become completely unbearable mentally. It doesn't need to be a full meal, but some kind of calorie top-up is essential.
[1] ...and it seems that different people get different amounts of calories from the same food, it's a gut flora thing.
Also, it would be good to simultaneously (somehow) check if the results depend on one's genetic or cultural bias towards eating in the morning or evening.