Something to consider to speed up modeling in MoI is to avoid filleting every single hard edge and use a rounder edge shader in your 3d application.
What I would called 'cosmetic' fillets (very small radius) can easily be handle that way.

It simplify models a lot, and help for further editing.
Depending of your render engine, it's a method that can even work for normal map baking.

When looking at those spaceship models (really amazing job), to get this amount of complexity, we probably need a better sub-object management (groups).

A really amazing concept are Shutline in Rhino :
https://www.youtube.com/watch?v=V_5oO9ehmoo

The workflow is super cool, non destructive and could help a lot to create those SF paneling details.
But it's some sort of 'post meshing' effect, and seems to create easily lots of nasty shading glitches too :(
I can only dream about a enhanced version of this concept in MoI, but I'm affraid it's probably 'too specialized' to fit in MoI toolset.