It is possible, just check my website (Media & Games section and select FPSC Landscape) and check out the screenshots on it and perhaps even the demo.
You just need to use some of the workarounds to make it work well. Do not use large scaled full landscapes, but use smaller items instead. Otherwise you will run into collision problems. Also do not use the landscape items as dynamic ones, it will bring FPSC on it's knees. Also don't go overboard and use 100's of trees, grass and mountains, you will kill your game for sure when it comes to framerates.