Good evening,
As for my restorer`s eye (as I`m a restorer): you are not right. This must be 28,800x28,800 raster (300 dpi, 96 inches), not the vector - as this is a painting (raster) from nature. Also you must understand that the natural resolution of this piece is lower than 30,000 - the style has not enough details and color transitions for 30,000.
But I can propose the 28,800 pixels raster to solve your problem.
Kind regards,
dr. S.Stegloff.