The current recommendation for best practices is to have a fistula placed once the estimated glomerular filtration rate is less than 20 milliliters per minute per 1.73 meters squared. This recommendation stems from the need to have a fistula placed at least 3 to 6 months before it is needed. This allows time for the fistula to develop and mature. This will also avoid exposure to dialysis catheters which are complicated by a higher risk of blood clots and infections.
The odor of urine does not have anything to do with kidney function and more likely represents odors derived from the foods and supplements that you are taking. The Chinese remedy that you mention could be responsible for some of the odor you mention in your urine.