Review on SIQIWO Multi Core QC 3.0 Type C Fast Charging Cable: High-Speed Sync Cord with 4 USB C Ports for Samsung Galaxy S21, S9 Plus, Note 20, LG V50, Google Pixel, PS5 - 4FT/2Pack by Ashton Dahmer

I connected three USB voltage testers to this cable, one for the input, one for the Quick Charge output and one for one of the other outputs. As I feared, plugging a fast charger into the fast charger output will increase the voltage on ALL outputs, not just this one. The splitter is thick enough that I thought it had an internal voltage regulator to keep the other outputs at safe levels, but that doesn't seem to be the case. If you plug it into a fast-charge capable power adapter and plug a fast-charge capable device into the Quick Charge output, you may damage any devices connected to the other outputs because they won't wait for the surge. BE CAREFUL.