Thanks, @Ian.M, I was brainstorming parallel as I had expandability in mind and was curious if I could achieve the same data output signaling & timing when all shift register inputs were wired to a singular MCU, (all shift register inputs wired in parallel to each other).
If I was designing something modular I assumed accounting for the number of modules, ie shift registers, would require more complex coding and/or circuitry than just designing them to operate in parallel.
I've never heard or used logism, thanks @jhpadjustable, I've been playing with LT Spice recently but still really new. Ill take a peek at logism.