The UI configuration should include the list of custom deployers available for use. This information should then be used to create a drop-down for custom deployer type instead of the current text box.
The assumption is that system admins will configure the deployers on the runtime server and will configure the UI.
The dtgov-ui.properties file should include something like this:
This list of deployer names should then be returned as a list in the configuration servlet's JSON and subsequently used in the deployment target UI. (each name in the CSV list above should correspond to a custom deployer that has been written and made available to the dtgov runtime).