High Prec is now a default for A5. I know it was buggy in A4, but are you sure it still is a problem. I think I saw a not in the readme.txt saying high prec was fixed at some stage.

In A4, I had alignment problems more than a few thousand quants from the origin. I posted a solution under something like "WED inaccuracies". Basically it involved building your world using a few large Map entities, as they have their own internal origin and maintain their internal consistency wherever they are placed in the larger world.

Gary.