Upgrade from H4 on mac -preserve old content?

Im upgrading from Halion 4 and still have ongoing cubase projects in H4 (also H3) concerned about possible issues with license replacement and content installation that may screw up my links to content saved in cubase project files and/or ability to use H4 and H3 in old projects. I remember years ago a previous Halion update (possibly H3 to H4) cost me a lot of hours having to sort these types of issues out with older projects.

My main questions are:

Since I need to activate H5 in order to receive H6 upgrade, is it necessary to do a full install of H5 to activate?

My understanding is that H6 contains all the content of H5 but would it still be safer to do a full install of H5 first?

Will either H5 or H6 installation mess up previous content links or ability to use H3 or H4 in my older cubase projects?

Any help creating an installation strategy would be appreciated as I’d like to avoid the hassle I had before though that may have been due to a change in the halion file system or something.