If the battery is not connected when the cables are connected it is not a problem to power the camera and monitor from the v-mount.
Not sure if i understand your point. Did you mean in-camera battery used in pair with V-Mount external battery?
It is not a hot-plugging issue. It is issue due DC power plus connected before minus (ground). In this scenario power splash somehow goes to HDMI cable and depending of luck burns or sometimes don't burns HDMI port in camera or in monitor.
HDMI and other USB-like plugs designed in the strict specification and "minus (ground)" always touched first.
But DC barrel and D-Tap and other DC connectors are designed in very random ways and it is unknown if "plus" connected before "minus (ground)", or if "minus (ground)" connected before "plus".