md2of2, yeah I was mainly concerned about the 740nm vs the 730nm but as Javaco points out it's close enough. I already ordered two of those guys even though they were on the expensive side, I like LedEngin a lot for some reason, so it's good. Could only find china and one seemingly old cree model of far red on ebay and aliexpress, so when the ledenigns appeared on ebay I just went with it.
I'll be using them, as prescribed, for a short period after lights out. But experimentation is definitely something I look forward to! like what caretaker has been doing in this thread. I just saw some kind of article where they've been studying the "cocklebur" whatever the heck that is, and it seems they definitely shortened the required amount of "night" in order for the plant to go into flower, with 730nm.