For the sake of clarity, you should always name the specific wavelengths because plants do not have human eyes and do not perceive these wavelengths just as we do as abstract "red" "green" but they use several photoreceptors that can absorb a much broader spectrum although one -phytochrome- does have a breaking point at around 700nm, where red becomes farred and the light is no more PAR.
Plants can sense, and use, farred up to 780nm, very intricate lab tests have shown even a bit further down into IR, but real IR - talking heat radiation - that is wavelengths starting from 1000nm to way beyond 5000nm, this is what is usually been used in IR radiators etc.. these wavelengths do only heat up the leaves and are not sensed by phytochrome.
As for using FR "IR" at the end of the day, it's a "sleep" initiation, or better, it helps speed up the conversion of Pr to Pfr, which usually happens in the dark from alone but needs close to one hour. So to use a FR-EOD can help the accumulation of the hormones that trigger the flowering response, in other words, it's like the night had extra hour added, so instead doing 12/12 you can do 13h of light, followed by 15mins 730nm FR and just 11h of night. In order to pump more light in the plant, or you let it at 12h and just help it in case it mucks around, some genetics may indeed need more than 12h of night for the finish.
Now outside in nature the evening dawn there the spectrum is totally dominated by farred so this puts plants already "to sleep" this is why outside light pollution or fullmoon light etc may not matter. In the end it's a matter of the ratio of PAR red : farred which is measured and weighted against and this creates a hormone state which will further dicate how the plant is going to react to the ambient light scenario. So it's possible if the plant in sleep is illuminated with adequately strong light all the Pfr will transform and "awaken" the plant, then reveg or delay of the flowering transition can indeed occur.
One last word, as the article above stated you can neutralize a night interruption with ending in FR - that only works for a few times, like 2-3 consecutive days, after that, the plant will behave as being PAR illuminated. It's because PAR light is sensed by other receptors as well. But that trick does e.g. work if an accidental night interruption happened during flower, then do FR-EOD and it will be much less chance of reveg. Also when having to work in the growspace at night using a green mono, the FR-EOD is helpful. But don't use FR excessively several times throughout the flowering night - it also can delay flowering then, Bugbee did a thorough test on this one with Cannabis as well.
Cheers
