I would crawl under and look carefully locate the cross brace under the front of the deck. Take pictures. Take a drill motor with you and a few small drill bits 1/16" maybe. Have the measurement of the HOLE . Depending where the brace is and where you feel the hole should be, look and see if it will fit. I'd then drill up next to the brace, release the bit leaving it in the deck so I could then crawl out and see where it comes thru. Now you can see where the brace is and lay the template on the deck where the hole will have to go. The only problen I can think of is if the carpet snags on the drill. Just be careful and stop the drill as soon as it breaks thru.
I did this on my Champion and knew that I had to cut thru the braces. I still went ahead and cut the braces. I put the comfort troll in so the screws would go thru the brace. Thus making the comfort troll bridge the brace.
When I lived in Atascadero, Jim the owner/maker of Comfort Troll was a friend. He lives in Atascadero and has his welding shop and tackle shop in Paso Robles.
I wish this was available 30+ years ago. Well worth it if you fish, especially like I used to fish. Tournaments all year fished every weekend.