The game clock needs to change. A fixed time-out per turn makes no sense given the nature of the way Magic is played.

Most turns go very quickly with a distinct minority taking far longer due to the real or perceived complexity of game-state. As with many other stateful games (e.g. Chess and Go), it ends up being a power-law distribution. Arena's game clock should reflect that.

We need to lower the mulligan-look phases to no more than 10 seconds each.

The initial turn should also only be 10 seconds as it's little more than a land-drop and, perhaps, a single spell.

Subsequent turn time-outs should be longer (20s?) and the time not utilized can be "banked" up to some fixed value (60s?) with its value displayed as a per-second count-down timer.

As has been mentioned many times on this forum, time spent by the engine executing automatic game actions should *not* be counted against any player's time. There are a huge variety of game-states that involve mass token generation and/or multi-shuffles and replacements that can (at present) result in a game win/loss due to a player "time-out" over which neither player can control.