The Imperial is big enough already! I would not bother scaling up,   I don't think you need to unless your were going to use two 18" in it.
the normal sized one is a couple hundred pounds I think.
I do not have the build experience that most have on the Imperial. And both  sets of Imperials had to be scaled down. One for fun and the other because it would not fit.

SO this is my humble opinion only.
But on the flip side if you have the room for one build it! and scale it if you want. There are so many methods. I used ratio on the 1/4, and completely redesigned the other.