Some 2 Stars theorycraft and hunches, I think 2 Stars synths are pretty easy, the program got 81% HQ on 100 simulated synths (0.9~ maxqual/curqual) with zero HQ mats (stats: 650craft/650control/430CP[highcp might have helped a bit too much]), just get Flawless Synth+ MaMa + PbP, I think ingenuity is basically going to be dead on 3 stars, it's decent now, but MaMa and PbP suffer zero penalty from level and they're already really good, also makes the Craftsmanship stat really bad compared to CP/Control, also MaMa will make whistle while you work a lot better than it is, and I think it's already worth using with "high-end" gear, but MaMa and Whistle have incredible synergy.
The current 2 Stars is waaay easier than old 3 stars 4 stars at release, it is harder than the initial implemented 2 stars, so I think we're not getting gear upgrades for crafting any time soon.
If we lower CP to 400, and up craftsmanship/control to bare minimum with 0/0 HQ mats we get:
42.0%~ HQ Average
0.74~ CurQuality/MaxQuality
CP is trully king.
There's an issue I think I fixed though, was happening with 1 stars as well more later.
Ok up to 62.2% / 0.78 after the fix, o wait that was with no good or excellents, actual HQ% @ 73.85% now, damn.