I think the major makers are simply marketing and selling a farce IMO.
It's gotten into the dogma of plant keeping and rather than suggest something different and actually doing some real research, they just go with what the customers are asking for and willing to shell out big bucks for.
They are not researchers, they are businesses.
They have $ to make.
Why argue when you can make a buck?
Maybe if they paid me to shut the hell up I might not ruin their product arguements/reasons for buying these
Same crap with light bulbs.
I've had temp differentials of 10F in my tanks. Some folks have noticed slow downs in their tanks in winter in some regions, but this might be due to lower bacterial rates for remineralization which occurs in the substrate.
So rather than temp/cold feet/ not compacting the substrate, increased flow rates/redox etc.............it's just the bacterial slowing down, there fore add a reptile preset heat pad(some are set to heat no more than 80F etc or some come with temp probes and temp controllers etc) or a styrofoam pad under the tank I think you'd be hard pressed to show any difference even in colder climes.
Going from sand/laterite mix with heating cables to flourite alone was a huge difference in improvement, this told me right away one thing.
Cables were NOT the reason for the great improvement in plant health, it was nutrients/bacteria/porosity of the substrate.
It had nothing to do with the heating cables.
I sold all my cables soon there after.
I've bugged George for years on this issue.