I'm pretty sure if Clete and JR would agree to some sort of constitutional element which explains what constitutes voluntary abdication on the part of the monarch, that the apparent chasm between them would be bridged, and easily.
In Catholicism, for comparison, if a pope teaches manifest heresy, not under duress, then he is claiming he's not the pope anymore. He quit. So therefore he's not the pope, so therefore the seat is vacant, so therefore the succession process proceeds according to the constitution, and this man is expelled from the pope's quarters.
If something that was like, manifest heresy, except in the civil realm, then this could be included in Enyart's proposal. The upshot is that the monarch can either explicitly quit, retire, abdicate, vacate; or, he can also implicitly do it. The implication just has to be foolproof. Any idiot, not just a high ranking judge or lawyer or lawmaker, can make the evaluation, assessment, and call, in the ideal case. The ideal case might not exist. Again going back to the Catholicism comparison, what is "manifest heresy"? Is that something any idiot can identify? Unfortunately not. It does actually take an expert or a team or college of them, to reliably identify manifest heresy. So Catholicism isn't the ideal system, in the sense that, it takes more than an idiot to decide authoritatively that a monarch has implicitly quit.
Perhaps in the civil realm there's something that even an idiot could see, means the monarch has quit (by implication).
I understand the angle, but abdication is not really the point under dispute.
If the king voluntarily abdicates, explicitly or by some unmistakable public act, then the throne is vacant and the succession process begins. That is not especially controversial.
But Clete’s proposal, as I understand it, is not merely about recognizing a vacancy. It is about creating a domestic legal mechanism by which a sitting king can be judged and removed.
Those are different categories.
Abdication means the king has vacated the office.
Removal means someone else has authority to declare that he may no longer occupy it.
So defining abdication may be useful, but it does not bridge the actual gap unless the alleged “implicit abdication” is truly unmistakable and not just judicial removal under another name.
If the king says, “I abdicate,” fine.
If the king publicly renounces the Constitution and says he no longer rules under it, fine, maybe that can be treated as vacancy by his own act.
But if judges, lawyers, experts, or a council must decide against the king’s denial that he has “implicitly abdicated,” then we are right back to the same jurisdiction problem:
Who has final earthly authority to make that determination?
If the answer is some court or process beneath the king, then that court or process is above him at the decisive point.