Rainford goby

Hey everyone....so my tank is about 4 and a half months old. Everything is doing very well. I have coraline algae growing on some things. I have lots of little astria stars, a good copepod population and those little white sponges growing on things. I have a 90 gallon with lots of LR...I was thinking of adding a Rainford goby, I currently have a scissortail dartfish, a yellow clown goby and a tanaka pygmy wrasse. I know these guys need a "established/mature tank"...I think that getting an established/mature tank is a different time frame for everyone. My water parameters seem to be steady and no drastic swings from what I can tell...I have an SPS coral that is doing well, a hammer a duncan, 2 different feather dusters and a blue linkia that is also doing well and shows signs of being healthy that I have had about a month now. I have margarita snails that are reproducing and so forth. Do you guys think adding this fish would be feasible or maybe hold off. Thanks for the input.