What happen if I connect only sata power to Enthoo Primo PWM HUB (also on any third party PWM HUBs) but not connect PWM connector to MB. Fans will run at full speed or I can damage hub?

I say that Enthoo Primo SE hub has PWM 4pin connector to MB,Sata Power and rest of fan connectors are 3 pin only. Instructions says : HUB adding PWM control to 3 pin fans and 5 of included fans are 3pin.

So can I connect only sata power without connecting 4pin pwn cable and all fans will be running safely?