To submit or not to submit GRE Scores for PhD programs in the United States
If the institution requires them they must be sent, of course. But, as you say, that is becoming more rare. 

But if they are not required I would only recommend sending them if they were truly superlative, which yours don't seem to be. I doubt that anyone would consider that you were hiding anything if they aren't required. 

Your application need to contain (only) reasons why you are well qualified for the position and highly likely to be a success. Don't include things that point in other directions unless required.