X2
You need to be offering oyster shell on the side. Crushed for quail, served out of the bag for chickens. Lack of calcium will cause soft egg shells.
Stress can cause soft shelled eggs...if a hen became frightened during the "putting on the shell" stage of laying, she will lay a softy. If a hen gets over heated, she will lay a soft egg.
For your quail, make sure to provide enough hidey places for security and keep them out of high traffic areas so they stay calm. You can add tree branches to the corners of the quail pen.
As for the goodies...there is nothing wrong with the goodies that you are feeding them. However make it only a once a day thing so they eat their feed.