You can easily verify yourself, as I did with a multimeter
that is exactly what i did - of course there is no 3.3V connected.
actually there is no logic connecting it as riser makes it's own 3.3V from 5V input...
Your confirmation that they share a ground and yet are electrically isolated shows you are clueless and I would DEFINITELY NOT listen to your advice.
sharing ground does not mean that devices can not be electrically isolated.
your TV and microwave owen share ground yet they are electrically isolated.
you are uneducated idiot no wonder you gather your "knowledge" from other idiots on youtube lol