Necere, you rock, and you shouldn't mind anyone who is sounding critical, you've done a great job, but it can never be perfect since everyone has different needs and expectations.
What you said is mostly true but I highlight this bit of the text because, respectfully, I think you have a wrong conclusion.
Firstly, with regards 'performance'. When the electricity reaches the motherboard or GPU, then it's further regulated by VRMs. As long as the voltage offered to the component remains within ATX specifications (+/- 5% voltage), there's no benefit to getting say 11.9V over getting 11.8V. In the case of the ST45SF-G, if you have the sense wire properly connected, this will be somewhat adjusted at load anyway.
In for example a 2 meter long copper stranded wire the voltage drop difference between 18 AWG and 16 AWG is 0.11V given a 4 ampere draw (e.g. PCIe full load). It's pretty small. Furthermore, the way the connectors are designed, multiple wires deliver same voltage. This further reduces the voltage drop, e.g. PCIe has 3 wires in parallel, and so the voltage drop difference between 18 AWG and 16 AWG is only 0.032V. Now totally insignificant.
Secondly, with regards sleeving, the main guy who is promoting 16 AWG for sleeving, is selling pins designed for 18 AWG. There do exist Molex MiniFit Jr pins for 16 AWG, but if he sold those then his sleeve won't fit with the wire he is selling, and these pins aren't intended for the crimper he is selling
The connectors are a fairly fixed item, it cannot be changed, but cable thickness can be changed, and thus a (small) performance improvement can be achieved by thicker cables, and the difference is more significant the higher the amperage passing through it.
The longer the span, the more a thicker cable is needed too. So in the situation with the M1, short cables, small gauge is acceptable. In the case of a large PSU and long cables, a thicker conductor is preferable.
What you said is mostly true but I highlight this bit of the text because, respectfully, I think you have a wrong conclusion.
Firstly, with regards 'performance'. When the electricity reaches the motherboard or GPU, then it's further regulated by VRMs. As long as the voltage offered to the component remains within ATX specifications (+/- 5% voltage), there's no benefit to getting say 11.9V over getting 11.8V. In the case of the ST45SF-G, if you have the sense wire properly connected, this will be somewhat adjusted at load anyway.
In for example a 2 meter long copper stranded wire the voltage drop difference between 18 AWG and 16 AWG is 0.11V given a 4 ampere draw (e.g. PCIe full load). It's pretty small. Furthermore, the way the connectors are designed, multiple wires deliver same voltage. This further reduces the voltage drop, e.g. PCIe has 3 wires in parallel, and so the voltage drop difference between 18 AWG and 16 AWG is only 0.032V. Now totally insignificant.
Secondly, with regards sleeving, the main guy who is promoting 16 AWG for sleeving, is selling pins designed for 18 AWG. There do exist Molex MiniFit Jr pins for 16 AWG, but if he sold those then his sleeve won't fit with the wire he is selling, and these pins aren't intended for the crimper he is selling