I just installed one in my
Bigfoot B19. I didn't want to have to put the dinette up and down every day when I was really the only one there. So dinette is now a permanent bed. I mounted mine on the divider wall, to the left as you come in the door. I needed an off-set to allow the arm to swing, since it can't clear the full height wall.
Here are some pictures of my install (sorry for the last one - 90 degrees off for some reason!). Not sure exactly what your layout looks like in there, since i've never been in a
Trillium, but I do like the Lagun. Gives me lots of space, a decent sized table when I need it and easy to dis-mount and put away if I don't need it at all. I plan to put a slightly larger table top (maybe 20"x30") on it over the winter - this old TV table ("16"x24") is a test run for size and base placement. I will be cutting the table top into 2 or 3 sections length-wise, and mount them using "butler tray" hinges so I can fold the side pieces up onto the middle section when not in use.
Be aware that you need to be able to access the end of the mounting bolts for the lock nuts. I had to add another off-set block to the mount, since I can't swing the whole thing over a bench or a short wall, like most folks would be, and the hinge end of the arm wouldn't quite clear the surface.