I just tested this:
If my leg/hr <0,8 after 5-6 hours playing, and a leg drops for me, i port to kadala and buy for 500 Shards, i get 2-3 legs. I tested it 5 times:
1. - 3 Legs from Kadala
2. - 2 Legs
3. - 0 Legs
4. - 2 Legs
5. - 2 Legs
after that, mostly 0 Leg drops for the next 2-3 Hours
Maybe all Rng, we dont know
someone tested this too?