Nice find! That would definitely help @RefDM
with his original wish to have a way to determine the type of backup. However, it does seem to have some issues. First, the DateCreated attribute corresponds to the Windows timestamp of the same name not the Backup Date/Time. I have a Synthetic Full set that began over a year ago but whose current Backup Date is a few weeks ago; the date shown by DateCreated is the former. I tried using "BackupTime" and "BackupDate", but neither pulled that info.
Additionally, although the BackupMethod and BackupComment fields return properly when I run this on a Server 2016 system, when I run this on my Win10 1803 system against the exact same backup file, those attributes return identical copies of the MacriumInfo content, i.e. more than what's expected and the Backup Comment nowhere to be found, just as if they were non-existent attribute names. I haven't dug into that one yet, but I didn't even know something like this was possible, so thanks for pointing me to it!
And RefDM, now that this is available, assuming it works as expected on your PC as well, if you want any help building a script that does something based on the backup type now that there's a way to pull it in a scripting environment, feel free to PM!