I like BS as an acronym, I talk a lot of it.
One thing Qon - the BS doesn't have to be restricted to a single line - as mid-late game arrives you can make another line perhaps.
There is also the option of feeding in three belts and still there's room for unloading.
If we place (and reserve place for) copper plate using assemblers at the beginning of the line. Then add:
Gears/green circuits, iron/steel, red circuits? - (electric furnaces and...?) - stone? (rail, boilers, brick - furnaces, walls).
The useful stuff. On that note: robots
I automate right through to robot frames. Crafting speed is fast after this. In this manner I can choose if I want logistics or construction bots as and when I use them. Crafting from engines is too slow. Unlike trains, engines are sufficient to kickstart and continue accumulating trains.
Rail is important to automate, you don't use a refill very often but who carries round stone and iron sticks.
For me the late (ideal) BS needs to cover the following:
Those basics we always assembled - assemblers, inserters, belts etc
Power - Poles, boilers, steam engines, accumulators, panels. If going large, highly recommended to get both solar and electric.
Mining - Drills, smelters -> electric smelters. Walls, lasers.
Oil - Refineries, pumpjacks, chemical plants (plus walls, lasers...)
Rail - engines, rails, signals if you want...
Robots - Electric engines - Flying Robot Frames
Plus repair packs and I've likely forgotten a bit.
For me the late game version allows me to continue doing what I used to do early game - grab stacks and get on with building stuff. Incorporating a personal building train to ferry me round and/or remotely deliver goods is a perfect accompaniment.
The original circuits and gears should leave room for expansion of them if needed. And then iron has to be doubled up for steel as it comes into play.
That third belt - the red circuits - for smelters and...? Bringing in the batteries and red circuits can disrupt the whole shebang quite quickly, forward planning for these would help me tidy up my BS.
![Very Happy :D](./images/smilies/icon_e_biggrin.gif)