DSB can you have a goby

You'll be fine with a goby, I have had a yellow watchman in my 50g bowfront for the last 5 years. No issues full reef system with a 5" sandbed. Yes, it tunnels; and yes, it does stir up the sand but what it does actually helps a DSB. It allows a little of the bad crap to come back out, but such a little amount it won't effect the tank, then it is removed by filtration, IE skimmer.