The operating system sets the maximum limit, and sys-clk added additional limits on handheld. The mariko hardware might incentivize some devs to work on getting around these limits but they are still in place at the moment. You can crank the OC to absurd levels on Lakka right now though.
switch lite oc to 1224/768 with uncaped handheld sys-clk is consume only 4.5-4.8 watt, or 3hrs gameplay, when playing witcher with disable dynamic res, it will cranck the fan to 99%, and you can hear some noise but still aceptable, not loud
when play like xeno 2 or dragon quest 11 with max graphics mod, the fan around 27-45%
more heat when youre charging, less heat when using battery only with uncaped gpu sysclk
real switch new model & lite capable gpu clock 1.26ghz faster than older model, but keep in mind is the hadware capable giving more amps to chipset or not, i think gamernexus have the answer for that