I read the first 4 and last 3 pages of your link, then gave up trying to find the exact place where we discussed the topic of the appointed Maronite Patriarch – but I do distinctly remember we had a discussion on it.
I recall that the last response on the matter was mine, and the gist of it was the following:
There are some factors we need to consider for the papal appointment.
First, that the Pope can appoint a bishop in a non-Latin Church is not unpatristic or uncanonical.
If the Synod of the local Church cannot choose a patriarch or local bishop for some reason OR within the time prescribed by the Canons, the Pope can legitimately make an appointment. We can otherwise certainly wait for another Ecumenical Council to make the decision, but I believe we are fortunate that we as Catholics can turn to the Pope in such instances. I do not see such instances as a unilateral, dictatorial action by the bishop of Rome, but is done by him for the good of the local Church, since each local Church needs a visible head. Would you agree with this (if the underlined portion above is/was indeed the case)?
Second, I know from my research on that period of Lebanese history that the Maronite Church was strongly divided between a pro-Arab faction and a pro-French faction.
Third, there does not seem to be a record of a single contemporary objection to the Pope’s appointment of the Patriarch. In fact, there are some sources who refer to the Patriarch’s ascension to the throne as an election.
In light of the three factors above, is it not possible that the Synod - knowing they could never agree on a choice for a Patriarch - agreed to submit the matter to the Pope? Is it not also possible that they submitted a list of names to the Pope for selection, and the Pope simply chose one of those candidates - which would fully explain why certain Maronite sources refer to the ascension as an election (since the Synod was not devoid of participation in the choice of candidate)?
I present these points for consideration in light of the fact that I really don’t know the story behind the appointment, aside from the fact that there was an appointment. I don’t see any reason so far for us to automatically assume that - even if it was an appointment - this was a
unilateral action by the Pope.
Those are my comments from my recollection of that past discussion (I don’t know why, but I keep thinking that the appointment was sometime in the 1930’s, not in the 50’s. I’m probably mistaken, but I hope we are referring to the same set of circumstances

).
Blessings,
Marduk