Let me expand on what I mean.
Shrimp Gobies by nature stay close to their burrow. This is based on a relationship with its shrimp, and is for protection.
Will some shrimp gobies sift sand. I am sure they will, but if they are following their natural habits I would anticipate it to be local to their surrounding burrow.
I will be the first to say, I am not a shrimp goby expert.
The goby may also act different if there is not a partnered shrimp.