I had a blast with this game ! Didn't go all 8 hours because I enjoyed giving every client a little story (melancholic musician staring at the morning fog, anxious mother who dropped her little one at the kindergarden for the first time, hyper middle-aged woman who can't stop talking about her startup project...) and I started being out of ideas. Went all the way to 5th hour though and it was a delight!
I'd suggest maybe add a few random events at the beginning of the hour (something makes noise and all tips are -$1 ; the weather is nice so all TN is reduced by 1 ; something broke and you have to pay $1D6...) for replayability, and maybe additional consequences depending on which tea the client prefers and which one they get (like you did with Herbal/Black) but that's just for additional spice.
That game is cozy, nice, cute, and really fun!