Yes, that is what I am talking about. Adding that 5 psi would certainly help prevent the flatspotting. Plus, flatspots can be small enough not to be noticeable. (I'm sure that a flatspot that would lightly shake the stuff in a trailer's cabinets is not enough to be noticeable from the tow vehicle.
Flat spotting is still a problem with tires under heavy rv trailers or any heavy loaded trailer that sat for a "long time" (1-2 years).
The OP would be wise have his trailers tires off the ground by blocking the trailer and removing them for "LONG TERM" storage (not just a few months in the winter).
If the trailer is stored for more years than the tires usable service time then he could sell them now ....and buy new ones later on.
Were all just guessing on time stored.
Goodyear website "storing rv tires"
Storing Your Vehicle Without Removing the Tires
*Ideally, a vehicle in storage should be placed on blocks to remove all weight from the tires. If the vehicle cannot be put on blocks, follow these steps for tire protection:
*Completely unload the vehicle so that minimum weight will be placed on the tires.
*Inflate tires to recommended operating pressure plus 25%. Ensure that the rim manufacturer’s inflation capacity is not exceeded.
*Be sure the storage surface is firm, clean, well drained and reasonably level.
*Avoid moving the vehicle during extremely cold weather.
*Move the vehicle at least every three months to prevent ozone cracking in the tire bulge area, as well as “flat-spotting” from the prolonged strain of sidewall and tread deflection.
*Adjust inflation before putting the vehicle back into service.***