So, is the tech saying the the alignment issue is both apparent and fixable but he suggests the factory do the job?
I would ask the tech to write down what he thinks is wrong. Its a little unclear and that is going to tell you if this is a factory issue or something you can get done on your own.
Depending if you are looking to claim a warranty item or not, you could find a shop that works on truck trailers and have the alignment checked.
If you want to read some in-depth material on this, RV.Net had a good writeup
on tire wear and the alignment fix.