Charger punches aren't OP. It's honestly only useful in very specific situations. If you try to charger punch a group of survivors (and survivors are rarely not in a group) you get melted.
Personally, I think charger punches are only useful in tight enclosed areas when the survivors are completely separated. And even then, if a lone survivor has a melee weapon, you still melt. If a lone survivor is in an open area, then survivor runs out of melee distance. Again, all viable situations being completely contingent on the survivor being alone.
But this is besides the point, I was suggesting the 1-second heal timer for various reasons, charger punching being one of. Other situations, such as jockey/hunter/smoker on a separated survivor is totally worth spamming heals so you don't die from other survivors shooting at you from a distance. Even having charged a survivor and moving them a large distance/hard to shoot area benefits from multiple heals. I often heal to survive just that little bit to try to ensure the incapacitation.