I can't speak to the CR6, but the Ender 3 you will need some upgrading for what you describe. The Ender 3 series does not have thermal runaway protection out of the box, so you would need to update the firmware. This is easily accomplished after either loading a bootloader (you would need an Arduino board to do so), or upgrading the mainboard to something like SKR Mini E3 which has a bootloader built in. from there, you have a choice of Marlin or several forks of Marlin to compile and load (I find Cheetah 5.0 to be the easiest)