What should the PSI be in the trailer?

Lantley wrote:
The issue with all this dialing in and weighing is that it does not give you any added margin. I don't want my tires to be exactly at their capacity. I want a bit of additional capacity or safety margin.
When I hit a run of pot holes and rough roads I want my tires to be able to withstand the additional impact.
My G rated Sailun's are up to the challenge. Aired to 110 PSI I have lots of margin to withstand the rough roads. MY E rated OEM tires were not up to the challenge and I ended up with blowouts forcing me to seek a better tire.
G rated Sailun's aired up to 110 have resolved all my tire issues.
No charts or individual wheel weights required.
I had the same issue with my prior RV. The D rated tires were not up to the challenge, but E rated tires aired to the max resolved my blowouts issues once again.
In the end you can weigh and air to match some mystical chart if you like but I will go with the max. PSI method.
I am referring to RV trailers only. Most other trailers have totally different characteristics and aerodynamics, the max. pressure method may not apply

I'm betting your OEM "E" rated tires weren't up to the job if you'd have traveled nothing but straight, smooth, and level roads. Yes, your Sailun tires will do a wonderful job at the higher pressures, but they also would most likely do a wonderful job at lower pressures too, like mine do. And provide your trailer with a probably less harsh ride while doing so. But what works for you is what you're searching for and you've found it. (I hate not having a "thumbs-up" emoticon.)