There's also this to consider.
Building|1.12|1.13|+/-
Smith|10%+2|20%+2|+10%
Factory|15%+4|25%+5|+10%+1
Nuclear Plant|15%+5|50%+8|+35%+3
Solar Plant|15%+5|25%+8|+10%+3
Spaceship Factory|25%+3|50%+8|+25%+5
Workshop|15%+2|20%+3|+5%+1
Furnace|15%+0|20%+0|+5%
Warehouse|25%+2|50%+2|+25%
Protectionism|-20%|-25%|+5%
Big Ben|-15%|-25%|+10%
All of those major increases are mid-late-game with the possible exceptions of Protectionism and on warehouses, which only applies to naval units that you could get to early-ish.
An average "production" city late game is going to see at least +35% more production, most likely +60%, plus an extra 4 raw. I don't understand how there can be a research balance question at all here in the late game if we can ramp up production by that much (gold too is up +50%, even if it's reduced on per pop by 1). There is no trade off on research cost at all at that point, there's just "build things slower".
In the early game the question is typically reversed as "build things faster", because they will cost more and almost none of those modifiers will yet apply (you might have furnaces to build units slightly faster, but unit costs stayed the same while buildings went up).
Smith|10%+2|20%+2|+10%
Factory|15%+4|25%+5|+10%+1
Nuclear Plant|15%+5|50%+8|+35%+3
Solar Plant|15%+5|25%+8|+10%+3
Spaceship Factory|25%+3|50%+8|+25%+5
Workshop|15%+2|20%+3|+5%+1
Furnace|15%+0|20%+0|+5%
Warehouse|25%+2|50%+2|+25%
Protectionism|-20%|-25%|+5%
Big Ben|-15%|-25%|+10%
All of those major increases are mid-late-game with the possible exceptions of Protectionism and on warehouses, which only applies to naval units that you could get to early-ish.
An average "production" city late game is going to see at least +35% more production, most likely +60%, plus an extra 4 raw. I don't understand how there can be a research balance question at all here in the late game if we can ramp up production by that much (gold too is up +50%, even if it's reduced on per pop by 1). There is no trade off on research cost at all at that point, there's just "build things slower".
In the early game the question is typically reversed as "build things faster", because they will cost more and almost none of those modifiers will yet apply (you might have furnaces to build units slightly faster, but unit costs stayed the same while buildings went up).