4 times a 'standard' terrain is plenty big enough! I made one for Midway. I got someone to modify the OL tools to let me build a framework, then used MS Excel to build up the numbers for each tile position so I could build it from scratch with correctly positioned tiles. The original OL tools had a size limit... which this exceeded... but the modified version had no practical limit. Worked OK..but was really boring to fly over!I also added some correctly sized carriers with the AI tricked to use them.

What killed it for me was trying to make a decent WW1 terrain with shell cratered no-man's-land and 3d trenches. Easy enough to do, but it had such an impact on framerates....and it showed up issues with SDOE's terrain lighting. You really couldn't pick out the detail when you flew over it. Underneath, SDOE has a brilliant physics engine, and offers a lot of scope. Where it falls down, and in truth, really always has, is in the limitations of the game tacked on it. Give SDOE a new renderer and a proper terrain engine, and it could STILL hold it's own today.