It helps with some techniques, but you do not need it. The Razor harness is a proof in itself:
The stock Razor 2 and 2.1 both have those included in the design.
Two drop attachment points (the Stealth has those too) and the B-Ring on the crotch strap would replace those adequately.
It looks, however, like nobody is using them to attach sidemount tanks. They are used for the pouch and equipment attachments only.
(as the manual says more or less and as far as I know it is not taught to use any of those for tank attachment either)
It seems like the problem with perception there is that people do not demonstrate diving any tanks but aluminum very often.
In most areas aluminum tanks can be found someplace and adding just a couple more (with a bit of extra pressure perhaps) extents range enough for most situation (doesn't it?) and those also look good on video without much effort (color and shininess, not better tank-trim).
Everything else is at least out of range of most cameras or the videos cannot be used because of lighting conditions very often.
But there are a few videos to be found where people are using most types of cylinder on one type of harness system or the other successfully in video friendly environments, or as short moments and single frames in a cave video.
As most harness system are comparable variances of the basic 'razor-style-harness', if you can find a video where someone is doing it you can assume it can be done with any system and for any diver some way.
I tried a lot of different cylinder types and from my point of view most are hard to get to work well without knowing before how it is done exactly.
Than it mostly seems to be a matter of bungee quality and placement of the cam band on the tank and you are done and can always dive that type in the future without further experiments (if you manage to always remember correctly).
