You almost got it with "render individual patch mixdowns"
For the violins in Standard version:
I need ~70 GB of storage for 5 (in reality 4) Mic Positions. This means 1 Mic Position has around 15 GB.
If i now make my own "Mixdown" exactly as I want it I will require additional 15 GB of storage space (as you wrote)
However what I could do now is to put the original 70GB ona a slow and cheap harddrive and only take my personal mixdown on my SDD.
This might not be the perfect way to go if you want to alter the mix in every track you do, but as my approch is "make it nice once and then use it forever" it would grant me 55GB for 5 Instruments --> 250 GB overall SDD space
I just want to remind you that even if you use only the reduced Standard version, Synchron Strings I ar not at all complete and the Legatopatches from three of five Instrumentsections belong to the most storage intensive patches.
And of course if VSL would provide any function like that they are forced to think how realistic it would be to use for the whole and whole Full Series and the fact, that the first parts of the Percussion and the still incomplete first part of the Strings are in Full version already nearly one TB (what means afaik nearly a half TB in Standard version) does not raise imho much hope that there will be any function which let you render the whole set of ptaches in your own mix. To me that seem to be a very time and storage intensiv tedious and clumsy solution, I suppose a reasonable use of the other RAM-saving features will allow you to keep and tweak your personal mix in a much smarter and more flexible way.