I'm currently farming ShT and Krennic on 9B and 9D, but after a month of farming, I already don't see the end of the tunnel. ShT 10 shards and Krennic around 12. So, it means that I would need around 2 years to get them 7*.
In 2 years, if the game still exists, they will be like JKG or CUP now. EA/CG should add another place to farm them, and I don't speak about this Chromium pack of course.
A refresh ! Of course, 50 crystals and you're even not sure to have a single shard....