The simple idea here, barring any precluding solution, is that any habitual renegers simply must be forced to pay on some average, more than they profit from habitually reneging. So if there are some chosen levels, and some cost associated to moving up level, there seems to be some equilibrium that can be set to negate the profits made be acting maliciously.
Then there is the problem of irrational or chaotically evil actors but they cannot have the incentive to make high cost accounts for the purpose of destroying the value created by moving up. Or in other words players that habitually get kicked down in level and have to pay a higher cost than those that move up, must necessarily spend most of their time at lower levels.
So there is simply incentive then to move up the ladder and a social cost to not adhering to the protocols.
This also levates the possibility of third party solutions, like players clubs, or insurances, or leagues and points that might be as favorable as bitcoin wallet providers, exchanges, or other services.
Furthermore, in the proposed solutions, although there is no need for players to reveal their strategies or hole cards, it might be made a requirement to do so in order to claims one’s equity in the pot. Without such a claim the equity might go to the other live players in the hand or at the table, or it might go into some large (jack)pot.