I currently have an evoker char with echo and efficiency traits. It should allow spell gems to cast twice using only one charge. I’ve encountered problems when using Ethereal gems created by real gems with the generous trait. It might be related to the fact that these ethereal gems only have one charge.
Most ethereal spell gems only cast one time, instead of twice as they should because of the echo+efficiency traits.
Ethereal Unanswered Prayers (“This spell casts three additional times…”) spell gems only cast one time instead of multiple (five?) times.