Hello
I'd say boss exotic drops are easy the lowest rng in the game, or at least how I percieve them. In past year I've done PEN enchants, BS and accessory include, I've done dream horse. But of all time I play game even back on deleted account. I only drop 1 Karanda heart, like 2 days ago. Only 1 exotic drop of all time.
That said I think it's good they have really rare drops and I don't think change would be for better. So how about adding some more items to boss loot table. Recently it seems that Lightstones are absolute pain in d azz. What if bosses have chance to drop some rare Lightstones, by rare I mean the expensive one only. You solve two problems at once. Cheers.