Well, I think that HLG do not realize what they are doing. The Puks have been around for at least 2 years now, the QB35 just six months or so and the 96elite is just a few weeks old. Other thing is, far-red EoD treatment is widely accepted but not many user here believe in the emerson effect. The most think it would anyway not work well with higher intensities or they think, they would get unwanted stretch.
HLG is just starting to distribute products for supplemental lighting like the QB35 and I think they wanted at first to bring some standard products to the market. The more often they get asked about products that contain additional far-red the faster they will bring out something appropriate. Pretty sure they will offer different versions of the QB35 incl. far-red sometime.
I know, they have an own pick and place bot with reflow oven. I would contact them directly and ask for QB35's with red, deep- and far-red diodes. Companies like LED-Tech.de or Cutter.com.au allow their customers own layouts and willingly produce customized products. HLG is able to do the same if they want and I would ask them to do the same for me.
These puks are 50 bucks? Really? I was never interested in these puks because the footprint is to small for me.
4 XP-Es in far-red I can get for less than 10 bucks, such an LDD with 700mA is even only 5 bucks and one still need a 12v driver to power the LDD. A typical product that is designed for a high profit margin but not with the customer in mind.
I would rather use 4 XP-Es mounted on 1ft strip PCBs with no silly LDD but with a small constant current driver. These 2-3$ e3ay drivers(5x 1w, 300mA or 5x 3w, 600mA) are of course no Meanwells but they are available in two versions, silver and gold. The gold ones use higher quality capacitors and the likes and you can get them too with 5years warranty. (PF: 95, efficiency 89%). A strip would also have much better distribution. With 2ft distance the distribution of such a puk is okay but my lights usually hung only 1ft above the canopy. I would get a hotspot directly below the puk but sides and corners would get only half that much.
Theoretically, you could even remove 3 red and 3 deep red Lumileds yourself and swap them for far-red diodes. I do not know which footprint the solder joints have(looks like 3535) and if you can only use Lumileds or if its possible to use Cree or Osram but with a hot air blower diodes can be easily removed. I have reflow soldered on kitchen hot plates or in the baking-oven, that works pretty well. Instructions can be found on youtube, if interested.