I've developed a method over the years that works great for me.
Rename C:\\Mach4Hobby to something like C:\\Mach4Hobby_3804
Install the new version of Mach4 and it'll create a new Mach4Hobby directory/folder.
Open two explorer windows side by side
Copy your Profiles, Screens, Macros, Plugins, license, maybe modules, any custom Lua files that might be called by anything in the screenset, over to the new version, same folders.
Done.
By renaming folders you can go back easily if you desire.
And, long as your upgrading after all this time, might as well install 4612, the new release version and ESS 270, or tomorrow, ESS 272!!
Tom