I know you can change the start menu command to add more options. You can also modify the inventoryscanner script to include a /F and schedule it. But as for the regular agent scan, I'm not 100%.
I would imagine you would need to make the changes in the ntstacfg.in# file to accomplish this, though i am not certain. You could not set it there, and then create a script to add the command to the local scheduler to occur at the startup of the system. I would be careful of this as depending on the number of systems on your core, full scans everytime a system restarts an cause a serious performamce hit to your core and inventory scanner.
I can create a task using a script looking for machines that haven't been scanned in a few days but in my environment, that is several thousand devices. I did go through file ntstacfg.in# and I couldn't find anything in there that I could use to set these parameters.
I would have to have something that allows some randomization so they don't all start sending inventories starting at 9 am if you know what I mean. Fortunately I do have an off-core inventory server so it shouldn't affect LANDesk that greatly.
Is there any part of the agent that I can force a full scan instead of a delta once per day since the delta doesn't seem to find all the changes such as Windows Services?