Identity Broker 4.X alongside 3.X

I'm installing Identity Broker 4.X for the first time and noticed that the installation process removed my 3.X service from the services pane. During the installation I specified a new database and installed to a non default directory (different to my 3.X install).

Just wanted to know whether we are able to install them both side by side or if this is not supported. It may be useful in a personal dev environment to have access to both, not sure about client sites however.

Two other things.
1) I've noticed too that while the Identity Broker 3.X service was removed from the services pane, the installation didn't seem to uninstall the existing version, it just unregistered the service. I've attached a screen shot. There may be a bug there.
2) Also I could not see in the installation doco or Version 3 to 4 notes whether side by side is supported or not. Which ever case it is, it might be worth adding it there if I havent simply over looked it.