So I think this issue with this is that the Stoneborn are exactly that. They aren't supposed to be dwarves. They are their own thing. They are only errantly called dwarves by the human race for whatever reason. I'm assuming it's because they share some qualities like muscularity, long beards, and are natural blacksmiths. I don't think, though, that they are supposed to be just another dwarf race, so any changes made to their bodies in terms of measurements and style should be focused on whether they think it fits whatever vision they have for this Stoneborn race, not whether it completely matches a stereotypical fantasy dwarf.
I do agree with the facial features being more distinct and maybe look more carved out.