Title. In other words, sbc recommended/optimal power supply is 5V4A but I use an 5V3A instead – will it damage or kill the sbc? The reasoning behind this is “an direct undervolting towards the system, for lower power draw and temps”.
Thanks in advance.
It’s hard to measure without some heavy equipment. A good indicator is where the charger came from–a cheap and light brick from AliExpress with a brand you’ve never heard of is probably going to be worse than an official RPi brick from AdaFruit or something.
As long as your device isn’t drawing more than the 3A, it’ll probably be fine.