Nice image but Looking at this in my minds eye I'm sure the East stand could be extended to another tier halfway between where it is now and the Leazes and John Hall wrapping around to the extended Galowgate, its a conversation that's being had for sure, I know there's also the issue with the right to light but as the Leazes Terrace is owned by a Saudi investment fund and without trying to be to conspiratorial its bound to have some if not very close links with the Pif so there could be some form of compliant movement
The Gallowgate can be extended to match the John Hall and Leazes, leaving a potential capacity of 65 -70000 which I believe would be the sweet spot whilst staying at a more complete St James park keeping the Heritage History and Tradition , bottom line if the money and the will is there by all involved including the authorities anything is possible