None of this seems to address power. maybe the pi zero is ok. For a pi4 you have...

regularfry · on June 3, 2023

With the zero 2 you can put the power through one port and the USB-OTG connection into the other. It's fine.

I don't actually know if you could power the zero fully through the OTG port, although I wouldn't be that surprised.

roeles · on June 5, 2023

You can, I recently did it.

Power on the Zero is connected to the pins, the power USB connector and the OTG USB connector. Afaik, there are no components in-between.

Eumenes · on June 3, 2023

Does a splitter cable exist?

satori99 · on June 3, 2023

You can buy cables or small splitter pcb's;