Thanks for taking the time to write that very full and clear reply Jonathan. I am with you on much of that though my needs are very different to yours.
I am interested in purely (largely generative) ‘modular’ performances rather than different modulars providing different voices within the framework of a traditional DAW timeline. Many people on here use Rack in combination with Eurorack hardware (of which I have none) to do this.
I am interested in the extent to which, and the best way, that one software modular can work with another and I guess the answer you have given is ‘through Ableton Live’. ‘Through Bitwig’ would be another popular answer these days too I expect. Lacking the sort of power in my boxes that you possess I am left wondering though whether the extra processor hit of running a fully fledged DAW is necessary. But maybe it is desirable.
VCV 1.0 will be very flexible. Voltage Modular is already very flexible. They will be/are able to host each other and/or offer direct means to communicate with each other.
However what I really want to work with are VCV Rack in combination with Softube Modular and the PulsarModular P900. These, though, are not very flexible at all; the latter will never change and Softube show little signs of interest in modifying their framework (I feel that every time I make requests they get filed in the circular filing cabinet). Those are the two though with, IMHO, very notable modules and sound quality (due to their analog modelling and internal oversampling). Neither offers midi/CV out and in all likelihood never will.
So, whilst they can be hosted in Rack (P900 through an additional layer of an AU wrapper), it is pretty much a one way process (audio & midi/CV in and audio out) rather than anything two way, and there is a latency hit, especially as patches become more complex within them. If you apply the same CV modulation from Rack to a Rack module and to a hosted module the results will be increasingly out of sync as the block size in the VST host is increased.
I lack the knowledge and experience to make a judgement a priori about whether there will be a way to improve this latency problem when VCV Rack is a VST and can be hosted in a DAW. Hence my question to you, which I think you have answered, that DAW PDC will help (but not at high rates of modulation).
Maybe I am just on a fool’s errand though and should just accept each software modular as it is and use it in independence of the others.