Can someone give me a few examples of situations where it takes more than 2 minutes to make a decision? I am not saying they do not exist...I'm only saying that I can't think of them. (Of course, I am excluding the very beginning of games when players may take a few minutes to look at unfamiliar cards, ask their opponent a question in chat about a new card with confusing text, etc. Taking several minutes makes total sense in those cases, but do not take place once the game starts moving along.)
I am trying to think back about games that I have played. Near the end, there are sometimes complicated situations where I need to stop and think. But that seems, to me, to take about 30 seconds at most. So, doubling that to 60 seconds has been way more than sufficient for my own game situations.
Of course, it's possible that my personal game approach--which is to have fun, and not to be super-competitive--takes less time than a really serious player needs. I'm not sure about this. I guess one way to check this is to look at games from the most recent tournament, to see how long the top players took in complicated situations. (Assuming there is a built-in game clock in the log.)
If I were designing the game from the ground up, knowing in advance about these slow-playing scumbags, I think I'd develop something like:
1. Before each person's first move, you have 2 or 3 minutes, which is enough time to look at any unfamiliar cards.
2. From then on, you have 30 seconds to move. Each time you move more quickly, you get to 'bank' 10 seconds from the time you did not spend. So, within a few turns, almost everyone would have a reserve of 30-60 seconds, which could be added to the 30 seconds you already have.
3 This reserve would be capped. Maybe at 3 minutes? Maybe at 5 minutes?? Not sure. That would be to avoid someone about to lose in a long game saying, "I have banked 10 minutes, I'm gonna use them all now, just to be a jerk."
4. Not sure what to do in cases of requests for an Undo. Probably just some set "penalty" to avoid situations where you ask me for an Undo, and I wait a super-long time to agree, just to unfairly exhaust your already-banked time. Maybe lose 30 seconds from the bank for each Undo request that is granted? Maybe lose half the time in your bank for each request that is granted?