very long addition time

Have any of you ever tried to make emulsion but with very long addition time? I mean 5 hours or so.

Not I. I don't have that kind of patience whistling but I'd love to hear about someone else's results. The outcome would depend on the recipe. Probably couldn't be one with ammonia. Temperature would matter.
A very long ripening time was once common practice. I've never tried that, either. Longest I've gone is an hour and a half.
There are a hundred-plus recipes and ideas out in the literature. It would be a fun project to try them all.

mine longest was less than 20 mins, you won!