It isn’t known if the primary port can power Cam V3 Pro as it is usually packaged with a 5V 2Amp power adapter. Even if it has enough juice to power it, then I doubt you’ll have access to the Floodlight software controls anyways.
I wonder if it will work if you set up the floodlight controls before hand with a V3 and then disconnect it to replace with a V4 or V3 Pro (if possible due to higher power requirements). IRRC, the floodlight remembers the old settings, but you’ll always need the V3 to make changes to the floodlight or to turn on the floodlight. It just becomes a “dumb” traditional PIR sensor floodlight.
In my opinion, it is too much of a hassle to do this and the floodlight is gimped as you no longer have automation options to turn on the floodlight either. It’s best to just use the auxiliary USB Type-A port to power a V4. If it is already in-use, then get a splitter USB cable to power another V4 camera as it should have enough power on the auxiliary port.
Type A male to splitter 2 micro male
Type A male to splitter 2 type a female
Female micro to splitter 2 micro male. Wyze also sells this which is Wyze Garage Door Controller Cable Splitter
or whichever one works for you