One sided will be less effective because there is a component of light from one side that transmits to the other. Wiithout that, you won't be able to have a long growth period & you will probably have to clean more often to prevent die-off at the base (due to shading).
Similarly if you run a lower-powered light, initially IME that is better so you don't photosaturate, but after you get a mature screen, that low power light will not penetrate as deep and you get the issue like above.
Increasing cleaning frequency would be required, but that's not necessarily a good thing. you want a long growth period, without die off. The thicker growth grows faster, there is a bit of an exponential phase to the growth cycle, and you want to capture that. There is a point of diminishing returns of course, so you want to harvest before that, and then don't over harvest - you want to stay on the leading edge of that growth curve, not from ground zero
