[when VE is used as an instrument in Logic, Logic basically treats it as a single instrument no matter how many VIs there are in that VE instance.
Ok, we're back to this. This: "as an instrument in Logic". The only time I connected {Logic} to VE Pro (and I do not believe there is a fundamental difference vis VE not-Pro) I had the VE Pro Server opened already. I don't know what the clause 'as an instrument' really represents; I was connecting to something outside of Logic, in other words. Is this bit something you are unaware of? I'm sure that you do not have to have it in Logic's process, as I don't even know how it can be merely an instrument in Logic like you believe it is. IE: it IS an 'instrument' to any DAW, but the plugin works to connect [Logic] to essentially a bridge, to another independent process which supports the VE or VE Pro host.
VE as 'an instrument in Logic' is not like VI as an instrument in Logic.
In any case, your instruments are going to be happier in VE than in Logic.
You open VE Service and then when you instantiate it 'as an instrument' you connect to it as a different process than Logic, which means that Logic is not the actual host of the VIs and its process determines nothing about CPU/cores.
Also, VE does work as a network. Open the 'Service' and when you connect to it, you are connecting to your computer as local host.
Also, too, I don't know anybody but Cyril that prefers using IAC. To me it's somewhat exotic.