DC motor don't come back in same position

I missed that bit.

I am tempted to ask WHY? What value is the knowledge of how much a gate is open?

In my own projects I have found that I usually never use the more esoteric features after the first few days.

Yes, u are right. But in my particular case, I need that half a gate to be opened a little more than other half. Sometime, gate is need to be closed in specific order. In this case is better (and simplest ) that half of gate to open a little more than other half. So ... is more to deal with code, but sometimes is necessary.