Optimum Leaf Temp vs. VPD

Been scouring the talk groups for leaf temp and VPD info... Seems the recommended leaf temp is 82-85F or so. With LEDs, usually a few degrees less than the room temp (measured with an IR gun). In my case running a bunch of HGL QB132s in a 4X4, maintaining a room temp of 85F is a problem. Maintaining a room temp of 75-78F with a RH of 55% or so is not a problem and the VPD monitor likes it (1.4 kPa in flower). What am I missing by not running at 82-85F leaf temp and a complimentary humidity for the same VPD ?

All depends on what the par meter is running. Might need to adjust your lights.

Leaf temperature directly affects photosynthesis. VPD (in which leaf temp, air temp and rh are factors) directly affects transpiration. Transpiration directly affects photosynthesis.

VPD just tells you what humidity to run for a specific temp. If you have good lights and your plants are getting plenty, and co2 is there for them to eat. Running higher temps allows the plants to grow more vigorously.