This is what I did at the end. What you have to do is work manually to create different air.inis. Then you add them into a folder named like #DBW_Jets. Inside you keep all the right sequence of folders STD/com/maddox/il2/objects and inside there is the air.ini folder that you want to activate. You do it from the jsgme, and it REPLACES the previous air.ini.
So, DO AT LEAST TWO DIFFERENT #DBW_whatever folders so you can revert back to your old air.ini. It's very simple and actually I found it very practical. I think that something like that is the right way to go forward and not all this talk about deleting versions of various planes, which is in any case a retro-step. The problem is that my little mod is a custom one, I put every planes I choose to, we need to standarize it. The reason is campaign building. I don't want it to be in the initial selector, because then it needs again its own folder, but an ini selector that would load too only the relevant maps will be very welcome.
About campaing building - One of the reasons that I am opposing deleting planes, is these poor campaing builders that they spent coutless hours only to realize that some of their planes won't be available in the next version of DBW(or UP). I use now 2 different air.ini, and everything is smooth. So why not?