To all of you guys - we found a way how to add a digital signature to custom configured installers without "going online" with our MSI configurator. So we'll soon implement this feature and any installer, including custom ones, will be signed with our digital signature.
There is currently no idle check in the program. However, you can use another solution. Enable the Ask User permission feature and set Auto-alow on timeout. If the user is there they can access or reject your remote connection request. If there are not there, you'll still be able to connect after a specified time.