Solar panels have bypass diodes about every 10V. In a partial shading situation it can look in the vicinity of a lower voltage. It will only look for small changes around that and not search the whole range. Many manuals tell you best to use no more than 2X battery voltage for best performance. I just bought a broken controller and it says not to use over 36V power point on a 12V battery. and 72V on a 24V battery even though it is rated for 100V. I use a 60V array on 12V and I have a controller that gets lost to in the low 20's. I built a control system that senses when voltage drops below 40V for more than 50 seconds. If it does, it disconnects solar for 5 seconds. Then it finds its way back to the upper 50's. What can you say, $#|+ programming. Panels are their own current limiters, this is their protection. Adding a capacitor can increase current surges way beyond what the controller FET can take. Personally I don't care if a controller burns up. I run a capacitor bank of about 8,000uf on the panels for my water heater controller. That can efficiently divert any extra power to heat water be it 5W or 500W. In the testing I have done it doesn't seem to help or hurt the tracking. I can not advise you to do this.
