Someone should rename the gens. I never know what people are refering to with the arbitrary names. Maybe gen a, b and c would work.

USB is intelligent. The device should draw as much current as it asks for. If the device is not detecting any host to do any data transfer with, then it is probably idling at lowest unit power load. I would bet it’s not bad for it in any way. As long as that power brick lives up to the standard.