From what I found (http://www.howtogeek.com/192772/what-is-the-system-reserved-partition-and-can-you-delete-it/ and other google links), System reserved partition is only used since Win7 and isn't "mandatory" (but is the default when installing on a fresh disk). But it looks like safe to assume when System reversed partition is detected, other Windows 7/8/10 partitions can be ignored (ie the bootmanager used for Windows is on the system reversed partition.