I see this as being a completely useless change because I can dig 1000 shells in half an hour if you know where to dig. Shells rates have gone down but they are still giving around 20+ shells per shovel. I find that nothing needs to be changed nor will it change.
What i recommend -
Digging in one spot you like
Knowing how to kill crabs quickly and where to move so you dont take damage
dig without interruptions such as pms.
Good luck have fun.