This was a big topic for us as newbies to rv'ing. We researched it like crazy before our maiden voyage. I recall being told that the max PSI is just that, the max and was advised to run just under the max to allow for pressure build up as we travelled. I run at about 65-68 PSI and when we get going the PSI gets up to the max 70 PSI, sometimes 72. Our maiden voyage was 4k miles and several smaller trips since without an issue. We don't exceed 65 mph at all. Too much at stake in and around our setup. Slower speed, more response time if something goes wrong or something in/on the road causes an issue.
We monitor our trailer tires with the EEZTire Tire Pressure Monitoring System - 4 Sensors (TPMS) https://www.amazon.com/dp/B009BE069Q..._7meXAbYQ7T1A6
This has been great to have on the trailer and will eventually expand it to 8 sensors for the truck tires too. Their customer service is phenomenal!
Our tires are about to the end of the road as far as time goes, so we will probably end up with the maxxis brand based on all we have read.