I wouldn't recommend building an entire system to simply do audio effects, given that you can find a buttload of physical rackmounted effects processors for damn near dirt. Seriously...if you can pay something like $180 for a used Lexicon LXP-15 ii (it was about 10X that when new!), why in the hell wouldn't you go for THAT rather than trying to cram functionality on that level into a module that goes in a Eurorack cab? And if patchability is the key here, just route all of the outboard gear's I/Os through some patchbays. I've been working like that for decades...and the idea DOES come with a "pedigree" of sorts, since I cribbed that from Syracuse's analog studio...

...which Uncle Bob designed. Not much better in the way of authorities than that!