I believe there is already a system out there, which forum I could not tell you.
But the bottm line is you can get many good trades using Williams system, but it is not the best fractal system.
The Fractal edge is based on Williams system the developers were at one time followers of Williams, but improved the system.

The drawbacks to both, at least for me is timeframe. I trade in different modes, depending on the day of week, or month, one day I scalp, another perhaps a few hours, then perhaps I will be in a few days.
The fractal systems are designed to give the best performance if used with daily charts.

but getting back to an ea, I have one made by TonyC, that would not trade at first, many changes have been made to it, but it would give you the best chance of getting a system to work. You are only going to be able to trade 1 direction, by this I mean it the EA decides to go short and you get stopped out, then once price goes back into the fractal it will place another short position, same if it goes long.

If it takes a trade on a trending day, your in the money, but other days your acount will dwindle.

What the EA does is finds the upper fractal, of the timeframe then the lower fractal, draws fibs, then waits for price to break the fractal, your order is placed and you then cross your fingers and hold on to your pants (if you are awake).

If you are interested I will find the orginal version and a modified version and post them tommorrow night.