I am sorry, but the logic here continues to escape me. Are tubeless tyres worth the high cost if you feel that you have to ride beyond the wear indicators?
If I do any sort of high-speed descending, and where I live, there is a good chance of that on every ride, I want to know that the tyres under me aren't edging closer ever more rapidly to blow-out condition.
I've also done the trick of putting the front tyre on the rear. But I found that only meant I had to replace the rear tyre quicker than if I had put on a fresh, new tyre.
And aren't you about the lay down thousands for a new TT bike? Maybe you should spend some of that one new back-up sets of tyres for the other bikes you already have.