Do I correctly understand that most (or at least several) of the key characters other than the MC have their dialog given entirely in a conLang of your own invention, with no translations provided? If so, I strongly urge you to rethink this plan.
Even Tolkien, who delighted in the linguistic aspects of his tales, gave his readers only a very few short passages of untranslated Elvish over the three volumes of LotR. (Galadrial's song in Lorien, The song og Gildor & co in the Woody End {a quatrain of which is repeated with variation by Sam in the Tower of Cirth Ungul}, Gandalf's one-line spell for fire in the snowy pass, a few words of orc-speech. The Writing on the Gates of Moria is translated for us, as is other elvish and dwarven). None of these are vital to the plot.
Having any significant amount of dialog that is simply meaningless words to the reader will, I suspect, be quite off-putting to many. Once you decide how to handle that, the choice will probably affect how to handle what others think the MC's name is.
This reminds me a bit of The Flying Sorceress by Larry Niven and David Gerald. In that SF novel, A major character is a space traveler, and his translation program renders his name as "As a color, shade of Purple-grey". The natives soon convert this to "The purple magician" or just "Purple". At the end it is revealed that this was a syllable-by-syllable translation, the original being:
As a mauve - Asimov
As a one-time joke this works, particularly since many of the character names are jokes, see the Wikipedia article. But it would be easy to overdo.
As an exercise, try reading the early Dorothy Sayers story "The Entertaining Episode of the Article in Question". In this story, there are several paragraphs of untranslated French dialog. French is of course not a conlang, and many people know it. But many modern English-speakers do not.
It turns out that the key clue is buried in this untranslated dialog.
A supposedly female character uses a masculine form, thereby proving that "she" is rally a man in disguise, and is the criminal. A one-letter and one-phoneme difference!
I have always felt this showed that Sayers expected most of her readers to know French well enough to have thought this a "fair" mystery, and that most current English-speakers will find it simply frustrating and pointless. It isn't that long a story, try it and see how you react, and then consider how an entire novel full of untranslated dialog might seem. The story is available here
