I think Windows 10 requires Agent 5.0.2? Not 100% sure on that.
You can transfer systems between ePO instances without modifying the McAfee Agent.
@tkinhead I've been using MA 4.8 P4 without any issue on Windows 10 so far.
FYI MA 4.8 P3 is the minimum supported agent on Windows 10 according to KB51573
I agree with using the "transfer systems" feature, it is straightforward and doesn't need any software change on the workstation. See KB79283 for steps to enable the feature.
Thanks a lot.