Is it safe to use 2 Power sources into a MacBook Pro 2016 15" I have a 4k monitor that has power over usb-c but it is only supplying 15W instead of what it advertised of 60W. So I was wondering if I could charge my Mac with its 87W power supply while having the monitor plugged in with its 15W while I sort out why my monitor is only suppling 15W and not its advertised 60W. Thanks.
Yes - that would be just fine. If you notice the battery draining you can always disconnect the display and leave the power connected so it shifts, then re-plug the display.