It appears that the Knights are repudiating their vows and forfeiting their claim to be a religious order, in favor of their identity as a medieval military order.  Fair enough.  The pope should acknowledge that they are not a religious order; he should dispense them from their vows, or clarify that the vows have no ecclesial significance; he should withdraw their patron and all clergy attached to the Knights; he should exclude the Knights from participating as religious in liturgical celebrations; and he should suspend or withdraw diplomatic recognition while the Holy See and the Knights work out whether or how they relate to each other going forward. It appears that the Knights are a cult, not within the church, but opposed to it. Perhaps Cardinal Burke will find himself more at home in that cult than in the church.