There was an out of range buffer zone scripted into 3.3.5 a few months ago, but now I've noticed there isn't one at all anymore. If someone runs out of range of your cast right before it finishes, the cast used to complete within a certain buffer range. Why was this removed? It seemed a bit more excessive than the way retail handled it but I recall there being a similar system at play.
It makes playing as a caster significantly more annoying. In situations like group PvP in WG or AV, it's almost impossible to even finish a single cast from the back line because everybody retreats right as the cast is about to finish, and if you move any closer to remedy that issue, you're 100% dead. It makes no sense why this was removed, and this is coming from a rogue main.