I'm using a USB Y-Cable with my Pi400 to power and use an old WD 2TB MyPassport Usb3.0 HDD. I'm using a separate 5v-1a PSU so the HDD doesn't have brown-outs. So far I've been using using the cable and brown-outs have disappeared and it boots up just fine.
I read that back-powering issues with the Pi4 can consist of failed boots and nothing else, but there doesn't seem to be a clear answer or verdict.
Is it safe to use, how can the Pi400 be damaged by this configuration?
I'm rewording the question to be more concise.
Can you please leave this question and delete the other one? thanks