U only Can use 3 Twisted Gems in total the 5-6-7dex one (Example: U have 5dex-6dex Twisted on AA and x1 7dex on Weapon That way will Work) If u have x2 5dex or x2 6dex or x7dex wont stack only 1 per type

And Soulbinder Gems u only can use 1 per set Leech doesnt stack so if u have x2 soulbinder gems in ur gear u are only getting 5%Leech (Not 10%)