You could try the meatloaf idea, nice and soft, also, my ds tolerated soft burgers, that sort of texture fairly well. I did use a food mill/grinder for a bit and mixed the beef in with plain yogurt and he gobbled that up. Small pieces of meatballs, that sort of thing went down easily. You could try diced lunchmeats- turkey, chicken- they are usually very soft, sort of high in sodium, but a small amount won't hurt. As long as ds is taking other foods well and shows no texture probs, then you could try it. FWIW, I don't think pureed meats would do any harm. He'll still be moving forward with finger feeding, and having one pureed item shouldn't make things go backwards, IYKWIM.
HTH