One of the problems with trailers (or toads) is that you usually can't fell it when there is a problem, tire leaking, brake dragging, etc.
Several years ago, I had an axle break on a car tow dolly, I never felt a thump, or jerk or anything. I was merrily driving down the road when I noticed cars behind me all the sudden stopping and flames (sparks) coming out from under the toad. I have no idea why the axle broke, bearing seized??, don't know.
I since have added a TPMS to my Toad rear wheels and also the Dolly wheels. The TPMS may have saved me on a recent trip out west.
On a long descent into Globe AZ, I was getting a temperature alarm on my left dolly wheel. The tire temperature was just over 200 deg (temperature inside wheel) . The right wheel was hanging around 160.
We stopped to allow things to cool and see why the left was so much hotter than the right. I discovered that the left axle had a small grease leak, and the grease on the brake calipers was causing it to hang. The left brake pads were nearly worn out. The right pads looked like almost new.
What would have happened if I didn't have the TPMS warning on my dolly wheels?? I suspect at some point, the tire would have overheated and blown.