I have written a number of times on the advisability of running trailer tires at the inflation molded on the tire sidewall.
Some posts dove deep into the Science behind the recommendation. I know this can make your eyes glaze over so how about just following what Goodyear says in their RV Tires information web page:
"Unless trying to resolve poor ride quality problems with an RV trailer,
it is recommended that trailer tires be inflated to the
pressure indicated on the sidewall of the tire. Trailer tires
experience significant lateral (side-to-side) loads due to vehicle sway
from uneven roads or passing vehicles. Using the inflation pressure
engraved on the sidewall will provide optimum load carrying capacity
and minimize heat build-up."