How to select frozen abalone you can see and grasp, but sealed in clear plastic?

I’m shopping for frozen Australian Green Lip Abalone (pre-packaged). They are pricey, thus selection matters! How do I pick the best one in the freezer case?

Red Flags: What should I avoid when inspecting the clear plastic packaging?

Color Grading: Does the intensity of the green fringe matter for taste or grade?

Size vs. Quality: Is there a 'sweet spot' for size when it comes to tenderness?

The store lets you hold abalone. But obviously, you can't unseal without purchase.