Rusto, another option would be to plant some beneficial rooted vegetation along the shoreline that would take up some of the nutrients in your pond (and deny some nutrients to the FA).
As I recall, some of the beneficial plants are very pretty and spread very slowly. I don't know which ones are the best choices, but if one of the experts gives you some good options, I believe you have several ladies in the house that might help you pick!
This alone will definitely NOT solve the problem, but it might make the job easier for the Tilapia, etc.
[Obviously, you need to pick portions of your shoreline that will not be altered during your long-term expansion plans.
