I'm not getting off-topic. And I don't think trying to get a dispensation to eat dinner with your heterodox acquaintances is really going to matter here anyway.
Everything continues to rest on making distinctions between different sorts of canonical infractions. Praying with heretics is an infraction, but so is continuing to exercise one's office after one is defrocked. And if roving across jurisdictions is not technically a fault, it is plainly questionable; I can hardly think that St. Pachomius would have approved.
I don't think that any of these are offenses of heresy; they all look like disciplinary issues to me. Or perhaps political offenses. After all, the true issue in all of this is who gets to lay claim to The Church. And in that light, political motivations pop out of everything and everything takes on a different meaning. Valentin must defeat the legitimacy of ROCOR's defrocking of him, so he is forced to deny the present legitimacy of ROCOR. And since ROCOR is now trying to erase the line between them and the MP (as they are ultimately expected to) it is sufficient to accuse them of the dreaded ecumenism.
It should be obvious that the starting point in this is nothing about heresy, but rather the irregularities of Valentin's personal situation. And I just don't see how they can be made to work. It requires a miracle of coincidental timing, if you will pardon the expression.
Refusing to pray with heretics is an act of disrespect, so I don't think any amount of taking around that point is going to be successful. And in the large, it is a political act.