Is there a limit to the number of characters that can be added to the ditapath?

Is there a limit to the number of characters that can be added to the ditapath?

Also, is this a reasonable practice...to simply put filenames for topics in the ditamap and then add folders to the ditapath? It seems like a simple solution which would allow you to reorganize files later without having to add paths to each topic in the ditamap.