maybe you are right, it is really not needed.
For example, the white board I got, the overcurrent limit is 4.5amps. I think if my pump runs dry, the power supply will shutdown as it is rated 2amps only. So perhaps really not a big deal.
As to no soft start, that can be programmed in the controller. I highly doubt the $125 icecap interface can do soft start. I really don't see why anyone would need to pay $125 to do something that can be done under $20.
The signal pin, based on the description, you are supposed to get data if the motor is still spinning or not, and even calculate RPM value. From looking at the signal in an oscilloscope, the signal seems random to me, or at least I could not make sense of it to figure how to calculate RPM. if the pump stops, the signal is low, but not always, sometimes it still puts out a square wave.
But regardless, if the motor stops spinning physically, BEMF signal stops and 24v output will automatically stop. So the pump will be safe regardless.
The ability to know the RPM value is nice, but not absolutely necessary.
From more searching/reading, I think those ebay brushless motor modules are used OEM to control electric bicycles and scooters, small motor operated tools, I would not be surprised if hoverboards use them.
To do it for multiple pumps, an arduino mega or a teensy 3 is needed, as there is only enough pins on arduino uno to control one motor. If going with a teensy 3, a wifi interface can be added. But again, the wifi interface is probably best done in the controller. The fish street T1 is marketed as a stand alone wifi controller, which I think does not really make sense. You really need to integrate it to a main controller.
I may just do it just for the sake of doing it.
