My sandbox tests show that not building that initial (100 fleet supply) of LF spam as quickly as possible basically loses the game (as TEC/Advent) if the enemy HW is 3 jumps or closer. So if you take any of your FFs (frigate factory) off line before then, your chance of losing in a frontline situation in 5s is pretty big seeing that 3 jumps separating HW is rather common (about 40 to 50% of the time) on those maps. You also don't have time to find out how far the enemy HW is before committing (or not) to that initial LF spam. By the time the scouts meet half-way (which would allow you to guesstimate the distance to the enemy HW), the window for the initial LFs spam is already over. So you have to blind-spam LFs initially assuming the [worst, i.e. that] enemy will be 3 jumps away. (Have even seen just 2 jumps separating HW in 5s, but those are rare.)
Now, when you're getting your first two roid/moons going (typically you can get both at the same time, but there are more weird maps situation generated by the sadomizer) you run out of funds for the sustained LF spam. That's an ok moment to relocate one factory, but not both. You'd still have funds to trickle some corvettes and/or LFs from one factory, perhaps with a bit of pauses in production. If you only find one colonizable roid/moon immediately, you probably won't run out funds for the LF spam at all, so in that case relocating any factory at that point is probably a bad idea, but I haven't tested the more crooked map starts in my sandbox yet.
You've got it backwards. What you need to do is build your frigate factories *as far away* from your enemy as possible so that he cannot destroy them. This is key. Build your factories on your backwater planets. To make up for the distance from the frontline, upgrade the the logistics slots to maximum, and max out the planet with frigate factories. This is how Doci and Grimm play and win.
That's a two-edged sword because it increases the time for the first reinforcements to arrive (after which they are pipelined). If you're talking about the 1v1 Grimm Doci game posted here, the reason why they have FFs further back is that they both aggressively take out construction frigates, so neither had much luck building FFs on the front lines. But they both tried to get FFs closer to the enemy as well, especially Grimm did. So I haven't seen them deliberately building the FFs furhter back in that game, except when the enemy gave them no other option by keeping the frontline worlds deprived of constructors. I haven't seen [recordings of] Doci or Grimm playing 5s, so I can't comment on what they do in those games.
It's a good question however if in 5s one should build backup FFs on the rear world(s) or if twin repair platforms for the initial cluster are a better investment because those can also help a retreating cap stay alive. I think that the twin repairs are a better initial choice [even though hardly anyone builds those on ICO early], but if you have enough funds and you somehow bought MA (as frontliner??) then building backup FFs might not be a bad idea either, and it would be cheaper with MA to build backup FFs than repair plats.
