I think light DPs should be air unblockable, especially on characters with meterless reversal DPs. There's no real reason to use the light version (unless you're playing Charlotta, but I don't think light DPs on the whole should be made safe like hers) when it poses the risk of getting counterhit and getting blocked by an empty jump at the same time. If lights were air unblockable but required stricter timing, mediums were invuln but air blockable, and heavies were the best of both worlds but had a long cooldown then all strengths would have a reason to exist