The problem
Panel sizing decisions get treated as a single number, R-value, when the real spec depends on four things at once: thickness, foam core type, surface finish, and fire rating. Get any one wrong and the room either underperforms thermally or fails a compliance check months after it’s built.
This decision looks the same whether the room is a grocery backroom cooler or a food processing coldroom. The physics doesn’t change based on industry, only the surface finish and compliance requirements do.