I no longer start a new factory from scratch if I want to do things differently. I use my existing - and now outdated - factory to launch a new one a few minutes run away.
Throw the first one away. Especially when starting a run, plan on throwing away the starter base.
I learned this trick watching AntiElitz speedruns. He'll build a manual bootstrap "factory" (really just mines and smelting) to get plates, then build a very-polished-through-iteration bootstrap base which builds all the development essentials - circuits, arms, belts, ammo, etc. That's used to build the real base.
I've done this once, but ended up spending three days building a rail in one direction because resource patches get bigger the further you are away from spawn. I ended up using nuclear powered trains to traverse it and it was still about 15 minutes to travel.
I learned this trick watching AntiElitz speedruns. He'll build a manual bootstrap "factory" (really just mines and smelting) to get plates, then build a very-polished-through-iteration bootstrap base which builds all the development essentials - circuits, arms, belts, ammo, etc. That's used to build the real base.