Ok, so "Manufactory (make conversion automatic)" just won the player-side nerf poll. Clever, sneaking that in to a "nerf" poll
But it does seem to highlight a wide desire to do something different with these. Specifically, to murder them and substitute automation.
The solution I think would be good for the short term, and the one that I think people were basically asking for, is:
1) Automate m<->c conversion. Specifically:
a) Remove all metal manufactories and crystal manufactories from the game (from the buy menu, from old saves, no longer generating them in new games, etc).
b) When you try to spend metal or crystal, and don't have enough, have instead deduct 1.5*(the amount you lack) from the other resource. If there's not enough of that, it just stalls like it normally has in the past.
c) Add a galaxy-wide control toggle for "disable automatic resource conversion", defaulting to off, which if on suppresses rule b)
Note: the current manufactory "multiplier" is 200/140 or about 1.43. I could have the conversion above be 1.4x instead of 1.5x, but I figured that the _slight_ nerf would be compensated by not having to bother about building or operating or whatever the actual physical devices, and 1.5 is just a simpler number to understand.
But I don't think this is going to be a stable solution in the long run because it just emphasizes something KDR_11k (and possibly others) brought up a while ago: metal and crystal are very close to conceptually interchangeable. To the point that I consider them the same thing when balancing (except when I'm making sure there aren't too many units that require way more m than c or vice versa).
Basically, why still have them as separate resources? The main reason for me right now is historical: that's the way it's been, and it'd be a pain to change. And that's true and valid: I simply don't have time to make all the changes that make sense, and I have to prioritize. But that's not a long-term-stable reason.
Simply combining them and calling it a day wouldn't be good, though, because that path of just removing/condensing everything in the game that is conceptually similar to something else would ultimately diminish the game into something a lot less complex and more abstract. So I try to avoid "condensation" like that unless the current state is being an active major annoyance or whatever. M+C doesn't really bother people, so it has stayed.
But I think we can do better.
Here's what I'm thinking would be the better long-term solution:
2) Combine metal and crystal into just metal, and reinvent crystal as something more distinct. Specifically:
a) For _anything_ that costs or produces metal or crystal, set the metal cost/production to (metal+crystal)/2 and then set the crystal cost/production to zero.
b) In old saves, convert all crystal spots and crystal harvesters to metal spots and metal harvesters. Also set stored-metal to (metal+crystal)/2.
c) In mapgen, seed metal spots wherever it would previously have seeded crystal spots.
d) Remove crystal harvesters from the build and tech menus.
e) Remove metal and crystal manufactories from the game
f) Now, to begin the reinvention of crystal: add a small amount of crystal production to the human home command station
g) Add capturable "crystal mines" (or whatever to call them) to maybe 1 out of 4 planets. These produce crystal over time once captured but can be destroyed and cannot be rebuilt.
h) Add "crystal caches", to maybe 1 out of 3 planets. These are basically distribution nodes that give only crystal (the normal distribution nodes would only give metal at this point).
i) Add crystal costs to units in accordance with their individual-unit strength. So mkI fighters and other mkI 196-cap stuff could cost 0 crystal, but starships could cost a chunk and even triangle ships could start costing a small amount of crystal at mkIII+ or something like that. The costs would be on a much lower scale than currently, say 1/100th or 1/1000th the normal scale. Production amounts on the home station, mines, and caches would be on this same scale.
j) Add a small ongoing crystal cost to matter converters (the pay-for-more-energy unit; collectors would still have no ongoing cost).
Note: the divide-by-2 part of (m+c)/2 is so the 999,999 storage cap can stay without affecting balance. I'd probably keep that storage cap the same for crystal though it may need to be reduced to the same 1/100th or 1/1000th scale as the costs... I think keeping the storage high is appropriate given that it's possible you could find yourself permanently low on crystal production (down to just the home station rate) if you pop all reachable caches and the AI destroys all the mines you were able to capture.
Anyway, this would change crystal from "like metal, but a different color" to a longer-term-planning resource that also serves as an extra way we can balance individually-more-powerful units (due to Lancaster's laws, etc).
Thoughts?
FWIW, I think I'll just stick with solution 1 for this next release (which I'd like to get out tomorrow if possible, we'll see) but solution 2 is something I'd like to pursue sooner rather than later unless it just totally goes over like a ton of bricks with y'all. Chronologically and in terms of "how off the current mechanic feels" the armor-rework takes precedence over this, but this solution would be a lot simpler than any of the workable armor-rework plans I've come up with