To be honest Brian you could go as intricate as you wanted to or not... We honestly just made the raceway then laid the liner over it let it hang over the edge then just stapled it in place and trimmed it... it worked just fine... and yes it molded to the corners just fine, the water shapes it into whatever structure is backing it. Much like a trashcan liner in a trash can.
The resin would work the same, its honestly just however you wanted to do it... when they make plywood tanks they use resin, but the liner may just be easier... Roll it out. staple. trim.... We bougth our online and i wanna say it was around 50 bucks for a roll the rize we needed, but someone like Viggen may know of a better connection for it locally since he is into the pond scene?
I believe that fish store in columbus uses the same method(ply wood and pond liner) on their coral grow out tanks in the back of their shop in the greenhouse.. they just do it more square and alot deeper.