BDPT is slow and in larger scenes very memory consuming, PT+PT without limit is too slow and does do a lot fireflies...
It would've been nice if you could use the limit but still had an option to some additional effect... Like a separate calculation or so.. Don't know if it's possible. Maxwell although slow does handle caustics pretty good I think... Nvidia has also came with some solution to do caustics with Iray which so far also did only fireflies, and even though is this effect many times unnecessary and sometimes even unwanted, there are situations where is nice and sometimes needed... So IMHO not something to be really a priority, but shouldn't be overlooked.... just sayin'...
