L3 to L4 Installation Instructions

I understand L3 and L4 can run side-by-side but I prefer only the latest version installed on my Win 10 machine.

I'd like settings, presets, partner purchases, edits, etc to migrate from L3 to L4 upon installation.

1) Does it make a difference if L3 is uninstalled prior to or after installation of L4? 

2) If it's okay to uninstall L3 prior to installation of L4 should I perform a standard uninstall or can I follow the complete uninstall instructions as provided by Anastasia Davis 5 months ago:

* Go to “Apps and Features” by right click on the Start button;
* Find Luminar there and click [Uninstall](you can also uninstall from the Control Panel);
* Type %appdata% in Search (folder Roaming should open);
* Find and delete the contents folder “Luminar 3";
* Go to Pictures -> Luminar Catalog and delete it;

If Anastasia's complete uninstall instructions for L3 are followed prior to install of L4 will it mitigate transfer of the aforementioned settings, add ons, etc.

3) If I uninstall L3 after installation of L4 can I perform the complete uninstall at that time or would doing so affect the L4 installation?

I'm asking because it's been my experience Windows gets laggy over time even when doing my best to keep it clean. Too many installs, uninstalls, re-installs, have a tendency to gunk Windows up.

Thank you.