Hello,
Are you changing both these settings provided below:
Step 1) When you created the package under Admin page >> Install Packages >> Client Install Settings, select the "Schedule Reboot" tab and set it to what you want here.
Step 2 )
Go to Clients page >> select a group >> Policies tab >> General Settings >> Restart Settings tab
Set it to what you need it to be.
Configuring both of these will get you what you need as you can supress the reboot by configuring these 2 settings.
Hope that helps!!