In my opinion, 6 minutes is the limit; any more would be excessive! If a player cannot complete their turn within this time limit, it indicates a lack of focus and poor decision-making. Such a gamer doesn't know how to properly allocate and use time (both their own and their opponent's), has many unnecessary actions, and often only starts thinking on their own turn, thus wasting a lot of time. People don't know how to value time, but it is irreversible, unlike money. And I think that faster thinking wouldn't hurt, so I vote for the minimum possible turn time. In this case, 4 minutes.