> That’s just piggybacking on a prediction of special relativity itself.

Let me stop you right now to inform you you don't understand how scientific theories are structured. Special relativity is not a prediction of special relativity. Likewise, 1+1=2 isn't a predict of arithmetic, it's the starting point.

If you are suggesting that string theory is somehow more fundamental or powerful than special relativity, and so SR is a mere consequence of ST, that’s a claim that probably requires more explanation or evidence.