No, sorry, information is wrong, you are still thinking backwards.
Not to worry, most people really don't understand it.
Let me start by saying recommended tire pressure in the manual or
on the swing arm, etc. is totally irrelevant, meaningless. ok, maybe not
useless, gives you a place to start and monitor psi, but has nothing
to do with the "correct" psi for your needs.
Tires do have a "safety notice" on the tire which should not be exceeded.
Like "MAX" tire pressure cold.
Where are you getting your tire pressures from? Best guess?
Motorcycle tires are all about getting the right amount of heat in them.
The right psi will change due to load on the tire, 1-2 riders, weight, riding style, temp, etc.
How do you know what the right psi is?
You measure the difference in cold psi to hot psi. That "IS" the only way.
For street 2-3 psi diff from cold to hot is good.
For track 5-6 psi cold to hot is good.
Tires create heat by flexing the carcass.
If you have selected the correct psi, bringing the tire to the
correct hot psi when it's cold out, which will requite lower psi to
create the right amount of flex in the tire to create the proper heat.
Now, when its hotter out, you will need to raise the psi to create
less flex in the tire or you will be creating to much heat in the tire.
cold out, set cold psi to raise 2-3 psi hot
Hot out, the same cold set psi may raise 4-5 psi hot. In this case
raising cold psi by like 2-3 psi, creating less flex, creating less heat may
only raise 2-3 psi
Like the safety notice on the tire of MAX cold psi, well if you load you and
your 300lb girlfriend, 60 cans of spam in the panniers for the weekend, you
might actually overload the tires, simply because you couldn't put enough
air in them by not going over max psi, tire would then flex to much and over heat. This is the reason a lot of the heavier touring bikes use a stiff wall tire to keep psi reasonable and reduce flex with heavier load. Of coarse there is max weight load too.
I can even tell how someone is riding at the track.
At the track I set my tires 31f/31r and when I pull in the pits end of session, I get 36f/36r, perfect.
I can set a friends bike 31f/31r and when they get back they have 36f/34r
which tells me the are pinning it, but not braking very hard. So.. drop cold to 31f/29r and check again looking to still get that 5-6psi rise in the front.
You get the idea.
So yes, if you tires where set correctly in the morning, they could
be under inflated in the afternoon.
"This is" how setting your psi works.
Once you check the cold to hot psi a few times you'll have it down.
Carry a gauge, measure when leaving, measure when pull over when hot.
Note the difference. Next morning adjust cold and do again until
you get it where you want like 2-3psi diff.