I am currently not interested in any build other then iOS & Android.
allowing me to specify this would save me some time and you some cpu time.
it would also be a good idea to allow me to specify if I want previously built versions of the app for the other targets to be deleted or left alone.
It doesn't affect the time that builds take - builds are run in parallel on separate boxes, so a webOS build doesn't have any bearing on your iOS or Android builds.
We may implement these granular controls at some point in the future, but our focus right now is on improving the stability of the service, fixing bugs, and adding new features.