Belgian GOLDEN ale and cacao nibs? Not too sure about that. I think The chocolate blends well with "darker " beers- I.e. Stouts, porters, maybe even browns and dubbels- because the sweetness or roasted favors from the darker caramel or roasted malts blends nicely with the chocolate. But a golden?? I think it will clash with the clean sweet pilsner malt. However, guess we will never know until someone tries it. So......I would go with1- 2 oz max for 5 gallons. This should give a slightly nuanced backdrop of cocoa. 4 oz may start overpowering the malt because it is a golden ale. Remember you could always add, but never take out. If it were a darker sweeter or more roasted beer, 4 oz would be minimum and 6-8 would give it a nice cocoa flavor. You could event throw an ounce or 2 in the mash and see how it effects the beer when it goes in fermenter.