It has not been removed... Photosynthesis is the reaction used for plants to turn the usable energy into something more useful to the plant. You cannot cut half a process out and just focus on one side when both of them work in tandem. Photosynthesis is endothermic. The light is not all converted to either plant fiber or heat. You are trying to say heat and photons are the same thing. They are not the same thing at all. They are both forms of energy, yes. They do both equate to the same total energy... but you can't say that one source creating 300W of heat and 700W of photons creates the same heat as one that creates 450W of hear and 550W of photons. The energy is converted to chemical energy, not just heat.
6CO2 + 6H2O -> C6H12O6 + 6O2
Plants have an overall conversion efficiency of 3%-6% the rest is emitted as heat and chlorophyll fluorescence. At 6% efficiency, 700w = 42W converted chemical energy and 550W = 33W converted energy. That is 11.5% more usable energy converted to chemical energy. Yes the numbers are small, but I wasn't arguing that they are huge, I was arguing that the usable energy, based off the efficiency, makes a difference and isn't all heat. Again, the levels emitted from the light source of different wavelengths impact the ratios of heat, chemical energy, and chlorophyll fluorescence. More testing needs to be done on these ratios to determine more accurate spectrum mapping for lights.
As a side note, depending on the environment of the plant, the added heat of an HPS bulb may help as plants are more efficient at converting energy in a specific temperature range. Having too much heat "evaporate" can harm the plants. At the same time, letting the plant emit the energy after absorption and conversion to chemical energy and chlorophyll fluorescence may be beneficial if you're running the room at a higher temperature. The water in the plant acts as an active cooling system and helps severely increase the surface area of the heat being emitted and overall reduces the hotspots that would result in burning had the energy been converted to heat at the light source as opposed to by the plant after the photosynthetic conversion.