As you develop prints, insoluble Silver Bromide gets converted into metallic Silver and Bromide, and the latter goes into solution in you developer. As this happens the developer becomes more and more restrained due to Bromide buildup. Whether you use BTAZ or Bromide in your original formula doesn't matter much. I have read on several occasions that Phenidone/DimezoneS is less sensitive to Bromide which means you could formulate a print developer based on these and some secondary dev agent (Hydroquinone, Ascorbic Acid, ...), and Bromide buildup won't matter as much.