Okay, I think I figured out what my problem is!
We have the full version, so I was wondering why I was not seeing an option where I could choose my previously custom-made reports in the Reporting Job window. However, I figured out that this is dependent on which reporting engine you choose (Microsoft SQL Reporting Services vs. Veeam Report Viewer). Choosing Report Viewer only allows you to use the predefined report packs, and does not allow you to select one of the custom-made ones. Selecting Microsoft SQL does allow you to choose a custom-made one, and it will send a slightly more detailed report in a PDF, Word or Excel file.
I like that choosing Microsoft SQL as the reporting engine allows me to do that. However, it still does not allow me to, for example, expand information on a specific virtual machine (i.e. to see when a NIC was added or modified). If it is just currently not possible to set up emailed reports like that (where I could choose my own custom Infrastructure changes report) and use Report Viewer to view the reports in a more interactive manner, is it possible that the functionality could be added in future software updates?
Thanks for all your help.