He can go fishing early on when the battery is limiting the voltage due to the PWM. He will have them back, cleaned and in a pan before he has to worry about getting to 15v.
It is a point though. Understanding the features that you get in any controller is important. When they are not present, you become the feature. No temp compensation means you have too change the float voltage in extremes. I don't need it while camping but in storage the rig will see -20 to 105f.
I am sure the C35 is a good PWM controller but for the money spent, there are options to be checked out.