The purchase of one or multiple licenses for VEP7 is not a downgrade. You are not loosing something by purchasing a license. In point of fact, you are keeping your VEP6 licenses. A downgrade would mean you are getting less than what you already have.Although I agree with you on some things, this has been explained to you several times now: VEP7 does not work with VEP6 so if you upgrade one license you can’t use the other ones, thus you’re loosing what you had.
Where does it say that if you upgrade one VEP7 license that suddenly VEP6 will not work? The only thing I have seen (albeit, I didnt see it from Paul, I saw others make the claim that Paul said this), is that VEP 6 will not communicate with VEP7. Meaning, if I have VEP7 running on my server, I cant use a VEP6 instance to communicate with it. This however is not a downgrade. It means, you have to continue to use what you currently have, which is VEP6 until all instances that you are going to use are upgraded. This isnt rocket science. To put it in the correct terms, this is not being able to use a piece of what you paid for until you have all the pieces.
I cant put a table together until I have purchased all three (or more) legs. If I decide to change the legs, I must still purchase all three (or more) of them before I can put the table together and use it. This means, I can purchase one leg at a time. I can even run it through various skupting tools to shape that leg how I want it to look. Until I have all three however, I cant put said table together. However, I can continue to use said table with the old legs, I just cant use said table by mixing and matching the legs (well, technically, I can, but it would look weird, for purposes of this analogy, lets just go with, I cant until all three or more legs are purchased and matching).
If my table legs are currently made of pine and I decide to upgrade the legs to a more sturdy oak, I dont suddenly LOOSE my pine legs by purchasing an oak leg. Heck, buying 3 oak legs doesnt make the 3 pine legs disappear.
Now, I get it, we are dealing with software, which is more esoteric than tangible goods. Vienna could very easily have broken this analogy by removing your VEP6 licenses when you purchase VEP7, through the magic of flipping a bit. However, they havent, thus the analogy works. You are still able to keep what you already have, you just cant use the new stuff until youve updated all the components.
Each instance of VEP is a component. It must be running the same version to communicate with another instance. All the components that wish to communicate must be running the same version. Luckily, you have 3 VEP6 licenses (or more) that will continue to communicate happily with each other, even if you have a VEP7 installation on the same machine. You need to upgrade all the components to VEP7 if you want to run VEP7. Since you are currently running VEP6, it isnt a downgrade from what you currently have. However, since you havent yet purchased all the components, ie. VEP7, it is not yet an upgrade. Thus, nothing changes, you continue to run what you have, not a downgrade.