The people that built the tire put a max pressure on it. You kind of have to trust they put some thought behind it.
More pressure will protect from pinch flats but there is max pressure the tire and rim will take.
The number one risk of too much pressure is blow the tire off the rim. The pressure is force on the tire bead and the tire is simply forced off the rim. Will one pound over force it off the rim - typically no. A tight rim you can go past and I have had some loose (small) rims that I could not even take a tire to the max.
The force on the bead is volume x pressure. That is why bigger tires will have a smaller pressure.
The other risk is blowing out the rim. Not as common but it can happen - typically only on a compromised rim.
As a big boy you should be on bigger tire like a 30mm - 35mm. A bigger tire takes a load better. In the 25mm tires they are for the most part targeting racers and racers rarely weight more than 180 lbs.
In an adult smaller road tire the max is typically targeted for 180 lbs and the min targeted for 110 lbs but that is not an industry standard. In between you can use linear interpolation.
You can find some 25mm tires that go 120 psi but according to the label this tire does not. You can test your tire at 120 but if it blows off the rim you cannot just get a new tube and 90 is good as you have stretched the bead - testing is destructive.
Some people think a higher pressure has more puncture (glass) flats and some think less and I am not going there. The answer is a quality puncture resistant tire.