If you're seeing Cl toxicity, you must be in the super arid desert portion of Hawaii. Cl isn't even in a problem in the mainland desert, where rainfall of less than 2 in/yr are common. If you think you are overloading on Cl, it is likely a leaching problem, where you have heavy soils and very little rainfall (<2 in/yr). In which case, this wouldn't be isolated to only centipedegrass, but prevalent on all turf species.
BTW, I know Chuck Murdoch very well -- he served on my committee for my MS degree. Chuck was great scientist. I've also known Jim Brosnan since his MS days at UMass. I wish I could say he was a scientist. Win some, lose some.
You puzzle me with your "no urea is used. All N is ammonium based ...." Urea converts to ammonium and CO2 very quickly after dissolution in water (hydrolysis reactions). You'll get more ammonium from urea than from any other fert app.
BTW, since your name is greendoctor, are we to assume you hold a doctoral degree? What did you study, and with whom? I would love to know you background.