Scaling by 6/5 isn't ideal, even with nearest sampling, as some lines will be doubled while others won't, unless of course the output can be 3200 x 2400.. If the DD wrapper would take care of the centering / stretching it'd be independent of the GPU and display.
I noticed the config tool requires .net 2, would it make sense to update that to .net 4? .net 2 isn't installed by default on W8.
Perhaps a Launch Game button in the tool might be handy too.