How high should I make my ceiling in my new shop,,,10 feet or 12 feet

Spray foam is vary expensive my shop is 42x96 16’ to trusses. I have 4” on ceiling and 3” on walls best investment. Keeps the shop solid as a rock as it’s a pole barn. Should have sprayed fire proof paint on it after but didn’t do the research soon enough. But for me were its gets hot in summer snows in winter, and holds everything together like it was all sheered walks definitely to me worth it View attachment 1716442578
This spray place I called said 1inch. I think the way you did the thickness is great. 1 inch they want 5500.