The only people who would not try for this are the same people who try to win the game in under 10 minutes. Doubling or even a 50% increase is too massive to not stop by for, which makes it mandatory. Mandatory research isn't a decision, it's do it or lose. As some one who's lost too many games because team can't control more then 2, no res will kill you everytime. Economic research/upgrades in other games work because it's independent of weapon research most of the time, along with simply having much more indepth economy and various factors. Empires just has res, that's it. You can't expand on that really in a worthwhile way without changing a lot of empires core.
Then sure, have that be the meta research after an armor and an engine, instead of mediums. At least you will have a decision point at ~10 minutes in, dependent on how badly you are losing map control - right now, the only deviation you would go for is enhanced RPGs, which is a 45 second detour in the same branch as mediums. Yaaay.
I like the idea of a second resource. What if there was a building that converted "res" to "energy"? This may make partial sense story-wise, as you couldn't generate energy without say, burning some resources for fuel. I'm not against an infinite energy generator either. Limited deposits of "res"/"energy" could also be added (keep the refinery nodes as they are now)? This would give some additional 1-time objectives for players in the early/mid game. As well as being able to have a single boost of resources early game to kick-start a team. I'd also like to see some veterancy of refineries. The longer they stay alive, the more output they get, which would incentivise teams to hold the key areas of the map. (And provide important targets for sabotage #usefulscout)
Res is already energy basically. res nodes can be interpreted as steam geysers or gas geysers. Thus refineries are actually generators >.< they've got nothing to refine unless they extract and refine petroleum which is useless, unless u wanna power some engines with its products lol Energy is the resource that makes most sense to have. but the economy doesn't support this concept. you can keep producing as much "energy" as you want, with no means to store it whatsoever and the buildings require no power to operate. I have no idea what "Resources" actually is. Very scary.
If we could interpret res as oil, vehicle factories could act as giant 3D-printers. An updated empires release could then show you how the vehicle you've chosen is printed :D Also all vehicles and buildings would be plastic.