Edit the file locally, but only upload the changes to the host. Create a smart scheme that interacts between the client and the host. Download only the parts of the file that need to be visible on the client. Upload changes to the host as the changes are made. No waiting for a complete file to download.
Network traffic is minimized.
This makes editing over a modem a pleasure. Changes made locally in the MS Windows client are reflected on the host immediately. The caching code that is required for editing host files can also be used for editing local files. The result is excellent performance. We achieve this performance by using a dynamic scheme to transfer only the minimum amount of data needed by the client program.