The 7/3 & 7/4 show does not have a material projection element to it, just accent lighting changes, some stars, etc. The fireworks are the real show, not the castle.
It’s a “360” show (meaning fireworks are shot off all around the park) so anywhere you can be with a decent view of the surrounding skies is usually reasonable. Of course, the show is framed to best be viewed when facing the castle... but other spots will do as well.
They usually open up non-traditional backstage areas on these crazy days, those can be options too to beat the crowds.
Have fun!