First of all, just wanted to say I added this mod back, and it looks a lot better. Thanks for all the hard work.

Here are the minor issues I've spotted:

PCB's can't be productivitied - Seems odd to me, since both the pcb substrates and the red circuits can be. Are you concerned that the productivity chains are too long?
Ferric Choloride & Vinyl Chloride can't be productivitied - Kind of the same thing here.
Plastic recipe can't be used with Fluid Permutations/GDIW - it gets reverted to the old plastics recipe when swapped.

Thanks for the notes.

I will investigate the plastic recipe/GDIW issue.

I'm not fundamentally concerned productivity chains are too long. My concern is more around theming. I may add settings (or a cross-cutting setting) to allow productivity on all intermediate recipes at some point. For the moment....

I think I will probably default PCBs to allow productivity. I was hesitant at first, thematically (i.e. 1 substrate in, 1 PCB out), but substrate isn't exactly a "unit" itself, it could be shaped/cut slightly differently to improve productivity, so I will probably do this.

For Ferric Chloride and Vinyl Chloride, this was more around keeping true to to real world input/output ratios, at some level. I may rely on a setting for these. Still thinking on it tho :)

Made a couple of those changes in latest.

Thanks! And yeah productivity doesn't make much sense for many reactions in Factorio, as there'd be very little wasteage anyway.