I have a 2013 Winnebago One 29L trailer. It is not qiute two years old. I have been noticing that the tires on the drivers side is wearing too much for their age. I just put on a new tire less than 30...
Overloaded on that side is most likely problem combined with tire pressure not at maximum. Have you ever weighed your trailer?
When most people say block up it means putting blocks under axles/frame to get tires off the ground. It is not a problem to use leveling blocks under the tires to level the trailer if that is what you meant.