So lets consider this using some numbers?
OK So gen and incomes vary wildly, after testing to get said numbers to make this post, things change depending on players (for instance in 3v3 a Req gen is 30 per player, while in 1v1 a Req gen is 60, also power is different etc etc). I also found a glitch with the AI, as they get a billion upgrades to cheat or something. All that being said lets consider some basic stuff. I think this is correct, feel free to correct me if its not.
-Assuming a 1v1 map, say Port Saunderus
-Base income is 260R 25P
-Once a Resource Node is upgraded, it is permanently upgraded (so if you lose a T3 node, it stays T3 for your opponent).
-All Req Gens give a base of 60R, 1st Req gen is 20P, each additional gen costs 20 + 7 * (number of req gens)
-All Power Gens give a base of 25P, 1st Power gen is 80R gives 25P, each additional gen costs 80 + 16 *(number of power gens)
-All 3 Resource upgrades are 250R 50P and takes 45 secs to upgrade.
-Your Req income increases by 15R per gen the upgrade affects (this appears unaffected by escalation).
-Your Power income increases by 6 per gen the upgrade affects (this appears unaffected by escalation).
So assuming the above is actually true for a normal 1 power, 1 req resource node no matter WHEN or WHICH upgrade you get it will take you over 16 mins to regain that lost Req and over 8 mins to regain that lost power. So presumably investing into resources upgrades before Escalation 1 is a big blunder. Also if you upgrade contested points and the enemy takes it, congratz you just saved them 250R and 50P per resource upgrade you invested.
What does this mean? To me this means upgrading resources before at least Escalation 1 will give you a massive resource deficit for a looong time. Infact what I infer is getting the resource upgrades in 1v1 may just be a complete waste as you will need to CONTROL the point for at least 8 minutes to start getting a return on power, so if you say upgrade a resource point at 6 minutes, you will get no power back until over 14 mins and no Req back until over 22 mins.**
Basically if your games aren't going at least 25 minutes you are 100% better off never getting the upgrades period.**