using epo 4.5 with agent 4.5 and vse 8.7 & vse 8.8.
What happes if i roll out engine 5600 an there are some clients with vse 8.7 and Patch lower then 5 ???
from the article you linked to in your post (the KB75459 one) it says this new engine is signed with a newer certificate that wont be recongised by the old VSE.
I would ask why you have VSE 8.7 around at all? Its pretty old and slower than 8.8.
also the hotfix it talks about is rated as mandatory so dont think there will be any mcafee workarounds.