I did the same thing with my KTM on the front deck of my E1.
Did you measure the tongue weight? I only checked the fit and didn't measure my tongue weight so I'm just curious.
The tiedown rings in the deck seemed a little sketchy also so I'm going to reinforce these in a way yet unknown. I also mounted a bike shoe and the wheels lined up perfectly on top of the frame rails so no issues with bike weight stressing the deck. I have a few more ideas and live in Minnesota so have all winter to get it done.