I think I understand what you are getting at. Let me see if my method jives with your thoughts.
I generally only ever build 10k of Infrastructure on Earth. And even this may be too much, but it's cheap so too much is way better than the alternative. If it's one of your initial builds, it can be slow. I usually do 5%, maybe jump it to 10% for a bit, then back down to 5 unless I'm pumping it up just to clear it from my list. That's all I ever need to build myself. I put ~500 on each baby making colony (Luna, Mars, usually Mercury) and any good planet with under 5 CC and decent minerals. (and in decent range of Earth in early game - don't send Infra on year long trips before you have other colonies started and self sufficient.
That 500 infra will grow as the colonists make their own. It's slow, but adds up over time and multiple starter colonies. Once that Colony reaches 0 CC, all that Infra that is there (both shipped to and built by colonists there) is available for you to move to the next colony. By the point it changes to that lovely shade of dark blue 0 CC, I've prob shipped another 2-5000 Infra in batches of 300-500 Civ Orders. Except for the initial starter Freighter and Colony ship needed to jump start the Civ Companies, I rarely ship Infra myself.
By the time a colony goes Blue, there is usually 10k+ Infra more than what I've shipped there.
Why do I ship more Infra when the colonists are already making it themselves? Speed. The number one reason for colonies (besides the Bonanza Worlds) is Pop Growth for me. Defensive Positions for Maintenance Base Colonies is a close second. I want to keep a decent way ahead of the Pop Limit to keep that juicy 5%+ Pop growth room to populate. Once you do this, you will note you can actually start shipping Infra off before it reaches the 0 CC mark and keep pop growth at it's current max.
Starting with the standard 500M pop start, Pop is always the tightest resource for me until mid to late game.
