Reference: https://budgetlightforum.com/t/-/6918 for the bent pipe things 
. I agree, science does not back up our pipes. I find if I slightly tip a light so the business end points towards the inside of the pipe, it increases readings quite a bit, whcih leads me to believe flooders may be over estimated. Might explain some of our (the bent pipe club members) unexplainable high readings on flooders. manxbuggy1/rdrfronty abd TurboBB did extensive tests of high quality lights with the pipe light box, and can show consistency, but I'm pretty sure vast majority were reflector based, not flooders, maybe all were reflector based. There weren't many off the shelf high end TIR optics or aspherics around at the time.