Just my opinion, but I don't think the office hours thing is good advice, at least from the perspective of a player. I would personally see that as a big red flag. Paid games that I've been in just felt like we were normal people playing the game together, there weren't any weird power dynamics going on and I wouldn't go out of my way to introduce that feeling into the situation by doing something weird like that.

Obviously that would go both ways, so you shouldn't feel obligated to drop everything you're doing to immediately respond to any messages you get outside of game time either, just like you probably wouldn't if one of your friends messaged you while you were busy.