Teardrops n Tiny Travel Trailers

I'm in the process of attaching the outer layer to my trailer. The plywood that I got is 2.7mm meranti. I'm currently letting the glue set for a bit on the front radius so I thought I would get some input. Based on any of your previous builds, do you think I should do a double layer of the plywood or is one layer sufficient? I have enough material but I'm somewhat concerned about how well a second layer will laminate and stay. I'll be doing either filon or fiberglass resin and mat for the skin (I have someone experienced in fiberglass who will help if I can get to that point by month's end; they'll be gone for a few weeks after that).

I just don't want a rock or something blowing through the wall. Granted, I was crawling around on the roof and it held up, so maybe it's fine; these are the kind of questions that inevitably crop up when you're going 'by the seat of the pants' the whole time. This is all new ground here.

I used 1/8" Baltic Birch plywood inside and out. On a 1x2 frame with 3/4 foam insulation between the sheets. I covered the entire outside with fiberglass cloth and epoxy and then painted with Monstaliner bedliner paint. I have never had a problem with rocks etc. poking holes. I had considered two layer of 1/8" pywood on the outside roof but once it is laminated together it is plenty strong. I had also considered adding thin diamond plate on the front for rock protection but it has held up so well I decide to leave it off to save weight. I think you will be fine with a single layer
Dan