Is it still necessary to cycle these supplements? And if so what is recommended?

there is some old evidence that claims that you shouldn't stay on L-Carnitine supplements too long because your body gets used to it. I never understood how that could be possible as long as the demand was always high for the need of L-Carnitine in the system....

I would recommend against cycling those supplements. The old evidence is outdated and mostly hypothesis. I stay on Energy Reserve all year round, and managed to keep myself pretty lean in this offseason in comparison to other off-seasons! I would never advise against stopping the Energy Reserve OR Lean Out.