Question about '3 in 1' Chargers

I am very interested in purchasing this 3 in 1 charger listed on Amazon (link). However, I have a concern related to how using this charger can affect charging my Apple Watch.

Basically, I would plug this charger into a 2.1A USB Port to charge (I understand this would be slow charging, which is totally fine). This charger comes with two USB outlets where one of the USB outlets will allow you to plug in the Apple Watch OEM Charger (the "puck" cable). My main concern is would plugging the Apple Watch USB cable into this '3 in 1 Wireless Charger' cause any harm to my actual Apple Watch (anything with overheating, or other kinds of damages to the battery, etc...), or even mess up the Apple Watch USB charging cable itself? I ask as I am unfamiliar how safe it is to plug the Apple Watch USB Charger into different USB ports outside the Apple outlet provided from the box, and just want to make sure I am not damaging my product. On the bright side, it seems that the wireless charging is Qi certified, and using only a 2.1A outlet, I don't see how it can negatively impact my iPhone's charging.

This question may come off as silly, but I came from a recent Android eco-system where it was notorious to have faulty USB-C cables and chargers be enough to destroy phones and devices, so figured I'd ask if this can be the case for my Apple Watch.