@JohanH - thanks for your reply! I also hope and think people who build commercial products have knowledge of this
But as a hobbyist, there are two ways to go - either you dont have to care or go bare minimum, if something happens its your own fault, or you can try to make is as safe as possible.
My idea was never to make this thread a information source for a commercial product. I wanted to try to make my own products as safe as possible since I have children around. With that in mind, i want to be on the safe side of things so some things i use from here might be exaggerated.
But my PCB (HLK-PM01 breakout) is working great, and I feel safe. I have had it outdoors (under roof covered in IP5* box, -20 to +30 aprox) and its been working for me for a couple of years now. Better than I had before, when i just stripped an old fake samsung charger.