If players are offered a choice between one PTO scenario and two ETO, they would choose the best one, irrespective of its theater. For that reason, I don't think that PTO scenarios are shunned by players. Good designs will always see some action. Were it the case due to a majority of inexperienced/unwilling players, having a max of one PTO scenario per round would ensure that no one is forced to play one. Not a big deal for a PTO-inclined player as he is also happy to play ETO (provided quality is there of course). Tournaments can only encourage players to play specialty ASL, not force them.