It's not often our community gets brought up on this board, and more often than not misinformation (though it's certainly not the poster's fault) is presented. That said, there is plenty, plenty evidence for Maronite Monothelitism, beyond the simple eye witness accounts of William of Tyre that Isa alluded to earlier in the thread. We have documentation of entire Maronite communities moving back and forth between their Monothelitism and the missionary attempts of the Syriac Orthodox, provided, ironically, by some of the first Maronite historians.
It should be known the first attempt at a Maronite history comes from the 15th century by one Jibral Ibn Al-Qilai, written in poor Arabic and even poorer Syriac as an epic poem recounting Maronite history. His penchant was sharing the multitude of Maronite persecutions (which are documented from a variety of sources, from Nestorians to Druze) as God's punishment for deviating from Rome and returning to Monothelitism. Every Maronite historian up to contemporary times have based their history on Jibral Ibn Al-Qilai, and rarely has their been a non cleric who has made an attempt to address Maronite history outside of that first source. When that attempt has been made---somewhat successfully---the responses have been to denounce their credential and person.
The "isolation" of the Maronites is an over emphasized historical event, and while it certainly occurred, it was one of geography and not culture. Relations with various Christian groups is also well documented, in fact, we have multiple Melkite Patriarchs denouncing Maronite migrations into their territories, subsequently taking from their flock (bearing in mind they shared the same liturgical patrimony at this time) and turning their people to Monothelitism. To counter, Maronite historians have tried to personally discredit these heirarchs throughout the centuries (despite maintaining that they were in communion with them by virtue of being in communion with Rome), culminating in simply negating their mentioning in Maronite history whatsoever.
I'd ask that these attempts at nation building be seen with some charity. These were persecuted people in incredibly difficult times in a region that has never seen ease. Jibral Ibn Al-Qilai was disingenuous with his people's origins, but the incredible acts of violence committed against his kind only encouraged his and his successor's attempts to build an identity for his people to latch onto and find support. And while communion with Rome was established in the 12th century (three different accounts of three different dates), that allegiance brought protection and pride that sustained an identity around which to coalesce in a hostile environment.
As a side, the incident with the Jesuits is correct, after Trent, mass burning of Maronite texts instituted an era of profound Latinization. This burning is why it is very unlikely a Maronite will ever see Maronite Shimo, their traditional divine office, or books of individual prayers. Maronite libraries in Aleppo preserve some of the works burned throughout what is now modern Lebanon. One of oldest liturgical source Maronites have is a Book of Direction, a book used in Syriac Churches to define liturgical (as well as civil in the case of Maronites) procedure and law. It could immediately be used to resurrect the Maronite's ancient rites, however, it is Monothelite, and rather than correct the theological errors and admit to history, we suffer the current synthetic liturgical and theological disparity.
Contemporary Maronite historians have per tradition relied on the exaggerated works of the past, but in a twist, have also somewhat, though just barely, acknowledged the adoption of Monothelitism in the face of fact. Starting with Pierre Dib, we see the discussion of Monothelitism as a "moral Monothelitism," in that semantically Maronite christology was expressed as one will, though their dogma was of Chalcedon in foundation. There remains to this day not a shred of historical evidence of a "moral Monothelitism," not that it is even possible to prove, some historians going further to say that these were peasants and unaware of their own theology (Peter Tayah, "Maronite Roots and Identity"), though I don't find demeaning your own people a proper form of argument. That, and every historian of the time, regardless of scholastic or christian denomination, have detailed the profound affect theological discussion played a role in the daily life of people of the era regardless of economic standing.
From Popes calling Maronites "heretics" and "former heretics" respectively, to the resistance to Rome some Maronite Patriarchs have shown since communion began, it is dishonest for an individual to hold on to the perpetual communion theory of the Maronites. Fortunately, though slowly but surely, some Maronite clerics have admitted, even publicly the events of the past, and in doing so lay a foundation for aiding the horrible situation the Maronites find themselves in today. Granted, Maronites themselves have duly played their own detrimental role; from the 1700's on we see the political drive for communion turn to a theological drive, and it is then the paradigm of Maronite identity is shaped after a Roman fashion. If we can be honest about our past from day one, we can be honest about the disingenuous Maronite experience and identity today.
Forgive the length, but hopefully this can be referred to when the question arises again on the forum. I’d be happy to expand on any one point, as well.