The RPA Scheduling Service is designed to work in conjunction with Robot Manager. The RPA Scheduling Service is responsible for keeping the machine logged in. Robot Manager provides the correct deployment package based on the Workgroup assigned in the CommonConfiguration file. The current version of the RPA Scheduling Service does not allow you to switch deployment packages.
If you want to switch packages in the middle of the day, you can use Task Scheduler to kill the Runtime process and reload it with another deployment package. Starting the Runtime with the project command line option allows you to specify a new deployment package.
The scheduler only unlocks, starts, and stops Runtime. The RuntimeConfig.xml is where you setup your project on startup. The most sensible route is to write a script that switches out RuntimeConfigs as necessary so that Runtime starts the desired project. Perhaps create a Windows task that switches out the file.
Currently there is no easy way to do this at the moment. If you are using Robot Manager, there is a feature that is planned to be rolled out in Q2 that allows you to change the VM's workgroup. The workgroup is linked to the Package Server and the assigned packages, therefore when you have the ability to change the workgroup, it will also change what solution is pulled from the package server and run on the VM. This feature is only available if you are using Robot Manager though.