I got the SPAL brushless fan for testing.

Part numbers on the fan:
VA109-ABL321
P/N-109A/SH 12V
10 R-05 8155

Very nice build quality. Cables are long and fan power wires look to be 10 AWG. The fan requires using their temperature sender which has electronics inside the sender that drive a control signal to the fan which turns the fan on via a pulse width signal (looks like the driver is open collector) and the fan electronics capacitor couples that signal to its electronics. The fan blades have a ring around the outside that spins with the blades. I think that is a good design for fan blade efficiency.

The temperature sender has four wires, Ground, Switched 12 volts, force full power (12 volts drives fan to full power) and the sensor output wired to the fan signal input. I will be testing that sender output to make a table of PW values at each temperature. So there are no relays and only one control input that forces the fan to full power.

The fan ramps up which takes 16 seconds to reach full speed. I think the ramp up time should be 5 seconds or less which would give engine idle speed control plenty of time to adjust to the added load.

The standby current of the fan is 36 ua. @ 12.5 volts which is very good for standby current.

The fan draws 22 amps in free air at 13.0 volts on the fan power. With the fan sitting on the OEM radiator that full speed current is 27 amps. So I would guess if I had the AC condenser also resisting air flow the full speed current would be around 30 amps.