Hi, I do not have a direct answer.,but with small structures insulation needs a different perspective. Any insulation in any cavity is not as good as even less insulation applied in a continuous fashion, so rigid insulation on the outside of walls, and ceiling. For the floor, go wood sub floor, rigid insulation, 1/2 inch plywoos.
This will provide a nice envelope so to speak, foil bubble insulation in cavities with air space works well here.
Now turn attention to orientation. Take care to install all doors, windows, with good seals and well calked.
Just my opinion, but after a lot of investigation in to tiny homes on wheels I realized they are usually a recreational vehicle, without a stamp or title, (but can be if you want)
I I am building on skids and keeping home height to 138 inches, so it can be tailored to new location., if needed, I also am going wider than 8 feet, so permit will be needed for moving but is not difficult to do.
I know so many things to consider