the answer depends on what the water is going to be used for.
if it is going to be put into the eyes, it should be buffered.
if you are going to water your roses with it, it would be a waste of time.
I really don't understand "pH balancing". Balance implies equality. Are you trying to make the water equal with itself ? people like to use the word balancing or balance or balanced with respect to minerals, but what the hell is "mineral balance" ????? To me , it's just a cool sounding word that means nothing. Like the gravel balance in my driveway. There is no balance, it's relative proportion that's meant most of the time, but since they don't put it that way, it's unclear. pH means negative logarithm of the hydrogen ion concentration. It's really the activity of the hydrogen ion that's important in most situations.
Does a little co2 present problems for you ? I think that wet lettuce leaves absorb co2 from the air also. In fact, plants absorb co2 from the air, as part of their life process. If people were afraid of co2, they might want to become carnivores to avoid it ! Even then, the blood of mammals contains co2. Whatever is one to do ?