Yes you can monitor multiple environments on different servers using command central.But you need to have platform manager installed in the SAG install location on those servers.
We did some test with those and we where not convinced of the extra value in 9.5.
I don’t know how much the usability has been increased on 9.6 but keep in mind that its
relative new component and software ag is still developing it and releasing a new version every new big release. (adding new components, possibility, etc)
We also noticed that platform manager has quite some impact on the performance of the IS.
Its probably not a big problem when you got enough resources, but i would recommend to test it.