Vince68 wrote:
You can if you want to. They are two separate programs, the same as Luminar 3 was a different program as Luminar 2018. I kept the 2018 version when I installed L3, and glad I did, as L3 was buggy and did not work right when it first came out.
If you like L3 and it works good for you, keep it until you are sure L4 works with no issues or bugs. Then delete L3 if you need the space.