Ultimate protection maybe a tvs and or isolatiing chip ciruit driving them. Few go that deep for led.
That big a diode is better for motor mods or big tranformer whistle/bell, stand alone whst./bell, etc. Maybe some in the In4007s (? Check me) could handle two I'd bet. Extras more versatile really.
The rectification is more about steadyness and flicker from the 60hz timing of the deep voltage drops vs a steadier voltage. Voltage is just a warning about a maximum voltage. Turn on is usually lower, not usually too much brightness variance from turn on to burn out voltage, but that can vary.
Brightness reduction with resistance would ad service hrs and is often a better way.
But back to flicker and rectification. A LED is a diode . So, if you add near any normal diode (or close matching led) in the opposing direction to an LED, you can provide the missing wave to the correct LED input and have full rectification with less diodes/led total e.g. you can use 2, light 2....or...one bridge rectifier + one LED = 5 diodes total, just one lit.
So a Bridge rectifier (or converter) suitable as a big universal supply to many led, but there are other more compact and simple ways too.
