It was a "title style".
Well, while that make an intresting ship - such proto-Edinbugh would be just as paper as Thunderer anyway - based on real design process, but never commmisioned or even laid down. Since changing turrets will, of course, require similar changes to hull, and this would be an totally different ship.
If we want to make high-tier ships for RN, or any nation, fpr that matter - they would be paper anyway, since we are allmost all out of surface ships which can be T9 or T10 material.