elite 2 Tired of tires

[FloraFauna]

While camping this week I noticed a slight sidewall bulge on my streetside rear tire.  I just replaced all my tow vehicle tires so was not excited about buying more tires right now, but a sidewall bulge is never a good thing.  I have the Goodyear Endurance ST tires on my Oliver and with the trailer only 3 years old and less than 10,000 total miles on the trailer, I was disappointed in the tire longevity/durability.  I have been running about 55 psi in the tires as a compromise on ride quality vs tread wear/mileage.  I know some of you run even less pressure to save the springs, but lower pressures do stress the sidewalls more. I then looked closer and the date stamps on the tires are late 2021 so the tires are actually about 5 years old, not 3 and 5 years is about the life of a trailer tire.  So despite low miles and inside storage, I am leaning toward replacing all 5 tires (including the spare) and increasing my running tire pressure some.  I abhor the idea of changing a streetside tire along the road on a trip after a blow out.

What would you do?  And don't assume your tires are the same age as your trailer.     

[BackofBeyond]

I would replace the one, put the spare on opposite side of the same axle. Put the other two best on the other axle. The most visible worn tire in as spare. Unless the tires have been in full sun, in the desert (say Phoenix), generally good until 6 - just inspect them regularly. Now the caveat - if I was headed out on a long-term trip - months, and headed up to AK, and beyond, different story. Do you run tire pressure monitors?