I can't answer the question conclusively, but with my laptop (Acer Predator and HP Pavilion x360) the device does not charge via the USB-C of the Targus. The dock has a separate charging cable that can be connected to the laptop, which could charge the laptop via the dock. However, I always use an external cable as well.

Yes, that's how it is with me too (ASUS VivoBook). It is not charged via USB-C. It has a separate power plug with different adapters. So you don't need the corresponding power adapter and can decide for yourself when to charge or not.

Since I've always had the laptops charging, I assume it's a BIOS setting in the laptop (or a capability of the laptop or not) whether it should/can charge via USB-C, and not in the dock. I'm not aware of any setting regarding the dock. It does have another USB-C port, but to be able to connect the 4x4k, I guess only the USB-C port I've always used (in the back) works, and that provides charging functionality on compatible laptops (as I said, as far as I know, not disengageable in the dock).