You need not as much far-red indoors because it increase stretching in the most situations.
CRI80 has only half the amount of far-red as CRI90 and usually the CRI90 plants are 2-4" taller.
Far-red can also trigger SAS syndrom(SAS = shadow avoidance syndrome) which means additional stretch, less nodes and less yield. I've experienced full SAS syndrome when I put my far-red timer inadvertently on "random", LOL!
Incredible stretching with 1' nodial spacings and stems soft as from rubber was the consequence and in the end 30% loss in yield, although after a week everything was repaired and set back to the correct values. And this caused from a 10w COB, which draws only 5,5w above my 10sft.
I would only use additional far-red when I was'nt limited in heights but I am.
3.000°k/CRI80 seems to have enough far-red.
Far-red can also shorten the reproduction cycle, in part by more than a week. Here you have to consider that the plants gets less light over the time. It could be necessary to compensate this with stronger light in order to achieve the same results like under CRI80.
I've added 20w of 660nm(12 Osram Oslom SSL horti-LED's@700mA) to 145w of CXB COB(4x CXB3590@1050mA), so 7,25 : 1 white : deepred. Far-red only as EOD flower trigger for 3+3 minutes.
I notice a little more stretching, and the leaves become bigger and pray more when I turn the deepred switch on.