My most significant peak load is 20mA for 35ms, happening every 3mn (radio sends ping).
One of the more important points in the TI paper is that there is only a small (about 5%) decrease in the coin cell lifetime when the peak current is 30 mA, compared to 15 mA.
Your peak current draw is substantially less than 30 mA. If it is really worth your time to research the perfect value of an added capacitor, go for it. I wouldn't.
Keep in mind that adding a resistor wastes energy.