I don't really think it's bad for flow because the player has to stay behind it's screen and react what's happening.
Being able to go away and take a cup of coffee while it's the ennemies turn is really what I call a bad flow. It's boring because you just have to wait, sometimes for several minutes.
If every ennemies actions could lead to something "like" a popup for a few seconds giving you the possibility to do something and to react... This is a better flow because player is involved in everyone's turn.
As I said I like TB games but it's actually to rigid to seems a little bit "real". I think the rules of D&D are made for fights to be playable (of course) but also to looks the more "realistic".