Hello,
Your english is at least as good as mine. English is'nt my native language either.
The plugins does'nt use that much space. Have you checked and calculated the space? They all use the same resources, so it's very far from triple the space they use.
VST2 use around 22 Mb for each instrument, - it's the same for VST3, AAX use only kb's for each, so that's 20 Mb only in total for the applications in the current VC9. I'm on Windows, so i don't know how much space the AU use.
But in contrast NKS files that many don't need use 1-2 GB space. For me that's more space than all the VC9 plugin formats use in total.
However - if you think, it's worth it for you.
I think it's still possible using the standalone installers for each application. They can be downloaded on the Arturia website. I can't remember which formats that can be deselected, but i think it's all of them.
It's perhaps also possible to get the options, if you deselect Silent Install in ASC. I can't remember. You'll have to try.
As AAX use so little space, then i think it perhaps is possible in ASC preferences to not set a path for a VST format, and then they will not be installed. (I'm not sure) - I don't know about AU though, but you can check that too.
If AU take about the same amount of space as a VST, and you only wan't to install one format in total, then you can at max save 1.5 GB space. Probably less.
BTW: Sometimes one format can do something another can't in different DAW's.
I assume the CLAP format is coming to Arturia.
No doubt even small amounts of space can be worth saving, if the files is'nt needed and one does'nt have much disk space.