I have the Montana 375FL, which is almost identical to the 376 and 377 model, with the exception of the loft and bathroom configured smaller in the 376 and 377 because of the steps leading to the loft. Other than that, they are identical floor plans.
My 375FL did come with a factory install hitch and originally I wanted to use it for my (already existing) cage that slides into a receiver hitch. I used it on my last 2 travel trailers.
However, immediately there were two problems with the 375FL. First, the shaft for the receiver was short. not that a hitch would not fit, but the cage would not slide all the way into the receiver without hitting the rear outside wall of the Montana first. (Actually, it hit the ladder first before inserting all the way).
So, I removed the sides and left the bottom part of the cage and it fit OK. However, when I put anything on the platform, it blocked that rear baggage door.
I keep all my blocks, electric cords, chocks and everything else I need to initially set up the trailer and unhitch from the truck. With that platform in the way, and with it loaded with anything, I'd have to remove everything off that platform before I could even open the baggage door.
It goes to say, I've never used the hitch for the cage, even with the sided removed, which would mean, in order to set up camp, that carrier would have to be unloaded first, even before getting boards out to put under the tires or jacks.
Anyway, before investing any money, think about what you are going to use that rear compartment for and then ask yourself if it's OK the door can't be opened until you unload the carrier blocking that door.
I made a novelty sign to insert in the receiver. From a practical standpoint, this is about all it's really good for using now.
