Well, imho it is not wise to do something like that before having met r/l at least once.

The reason for this is that no matter how great you get along talking, and no matter how much you like each otherīs picture, it might still be that the chemistry is wrong - meaning, one of you or even both might dislike each otherīs scent/taste/way to talk and to move... simply all the things that usually give a "first impression", and that make you want a person, or be repulsed by a person, or be indifferent to a person.

My opinion might be seen as critical and unwanted to you - but if you only want "fine, great idea, go ahead with it" answers, you have obviously already made your decision, and do not really require any feedback.

From my point of view, jumping from online to live-in real life is plain crazy. (Yes, that is critical.)

It might be an option if the two of you have no children or other family to live with, and if you two are located in the same city, and the moving-in thing does not involve quitting your job or having to leave all your friends and acquaintances several states away. But only then.

Please be aware that there are even couples who know each other well and are basically happy with each other, but still found the living-together thing does not work for them.

I donīt know if this decision to move in together was yours or his - but if it was his, I would question that VERY much.

Which reason exactly speaks againts a first casual meeting to get to know each other in real life? Makes me wonder. And not in a good way.

The best thing would be to take the relationship to r/l and see if it works. If it does not work while you live in separate flats/houses, there is no way it will work when being in the same place together all the time.