"why build the whole 'project' every time you save one of the files"
How likely is it that you're going to want to change more than one of the files that make up the project before saving the "project" itself? Unlikely, I'd think. 99% of the time you either only have one file in the first place (the agent code) or you just want to make a change to one of the files. In this case you really don't want to have to save to files every time you make one change. It's driving me crazy.