It is not as simple in your case to just say it needs more or less of something.
There is a very important dynamic between the amount of light and the temperature. They work together and how quickly nutrients are absorbed is very dependent upon temperature. I know your 2 fixtures arent really pumping out 2400 watts or the plants would be dead.
Below a certain temperature, some nutrients are less utilized, and above a certain temperature the same is true. As mentioned above if P is an issue, say too much, that is a temperature issue in your case.
So that is why it can be difficult to just look at your situation and say --
Magnesium for example becomes less and less available as temperature rises.
I know you are hesitant to discuss the power trip situation but that is a better key to success than looking at the specifics of those leaves.
There are full on electricians here that will solve the breaker issue if you let them.
800 watts of light and fans is enough, we could get you there if interested.
At 75f, you would have a whole different grow. At 80f, you would be blown away by how they grow and utilize the nutrients much better and faster.
They WILL grow fine at your temps, but the issues you worry about are due to temperature issues, not a mix problem (imo).