Note also that tyre pressure changes 0.1 bar per 10 C deg, 1.45 psi per 18 F.
So if you measure or adjust tyre pressure on cold morning/ bike has been sitting in a cold garage, or hot day/ after you have been riding on the streets/ tyre is hot, it will make a difference.
Of course. Because of this, many/most TPM systems temperature normalize the display of pressure. Regardless, it's a standard practice to measure pressure when tires are cold so the measurement is inherently normalized.
My guess is that a lower-pressure tire will tend to warm faster because it will have more flex in the carcass and the flex-friction produces heat.