This bug was not fixed sooner as we were not aware this was happening with the artifact (as tends to be the case with any bug until it is fixed - we don't purposely release bugs). When you look at rank 120 and 160, the damage was splitting correctly. The issue was only with rank 200 which the breakthrough for the rank is "Installs Empowered Channeling Tactical Mod" nothing about damage no longer splitting. The explosion not splitting at rank 200 is a bug that players have been able to capitalize on to deal extremely good AoE damage off a primarily single target ability. The concept behind the rank 120 was to give a small AoE component to Heat Vision (as it does, just rank 200 was broken) and that AoE was meant to follow through to every subsequent rank.