I agree with this. It's even questionable whether or not light reflective tape even makes a difference. What does make a difference is the shear size, density and overall height above water for the target. My personal boat radar (Garmin Fantom 18HD) can acquire targets as small as birds and crab pot floats from as far as two miles out.......depending on surface conditions.Since none of them are actually publishing their radar cross sections (RSC) or performance in any actual scientific way, I'd consider any/all claims that they are "reflective" in any meaningful way as bogus marketing fluff.
I carry both a depth deployable SMB and a larger surface only SMB. I'd say that the larger and "higher" you can get the target, the more chance of it being picked up on radar. Also, if you ever do end up on the "drift" in hope of being spotted, it nice to have a means of attaching some of your ditchable weight to the bottom of your SMB to keep it upright when / if you get tired.
PS: Carry a signal mirror for day and a strobe for night.
PSPS. Nautilus Lifeline ( I have the older version with the VHF radio option)