For now Coruscant as Exegol isn’t happening. I’ve already completely abandoned making the DSII Coruscant since it created way too many issues, and since there’s already a smoother alternative in the form of making it the same Death Star from ANH. Exegol being Coruscant only creates one in the question of how a massive fleet stayed hidden on the former Galactic Capital. If that can be solved the only obstacle will be technical, which, like with turning Pasaana Tropical, are big enough to postpone indefinitely, as I, at least for the time being, lack the necessary skills to pull it off.