Aliexpress escrow protection is also no magic bullet.
My wife bought a petticoat from there and it arrived completely unassembled. It was just fabric!
She put a complaint in and aliexpress ruled that she could make a petticoat from the fabric so only refunded 50%!
Why not put the relay after that AC power supply (where it is 35v) that way you can switch it as fast as you want (if this had a multifunction controller you could multiple relays, one for each channel)
The board requires 5 volts to run its own circuitry.
The board also has a regulator on it which will take varied voltages and bring it down to 5 volts.
So you can power the board directly with 5 volts or connect the regulator (via a jumper) and the regulator will sort out the voltage.
Does...