I rechecked the hydrometer with 59* water and it reads 1.000, so i beleive I can rule that out.
I agree- 1.011 is high, and I was expecting the brett and bugs to chew through everything (the partial mash and DME I used are in OP). The brett is definitely working, and I observe that it a pellicle is re-forming now that the beer is at 66* in the basement.
I will ride this out, as it is quite nice tasting now. It really reminds me of some of the lambic on cask my wife and I had in Belgium this spring. We both can take a lot of sour and funk! If I ever do bottle it, I will bottle some at very low CO2 volume, to that style, rather than the champagne-like effervescence of gueuze.
C'mon, bugs! I can get 1.004 with WY3711, for goodness sake.