You might have a look at The Dave Method if you ultimately want your parts at life size.
If you work in metric units, you could just set units to meters and work with them as if they are millimeters. It won’t matter when you export the STL file anyway.
This is already available in SketchUp Pro and has been for years.
Some of that already exists in SketchUp Pro and there are extensions that do some of it. It seems with every version of SketchUp there are more features related to BIM.
FWIW, it sounds like you need to be using SketchUp Pro.