One of the issues that has not been mentioned here is the way that the rims on a trailer have side to side forces applied to them. This is more apparent at a low speed, but still is something to look at when looking at the design of the wheel.
The wheel was designed for an application. Is the application one that the wheel was designed for? The side to side stresses will always be applied when changing the trailer from a straight ahead movement to going around a corner. There is a tremendous stress that is placed on the rim as you swing the trailer. The only way I can envision placing that kind of stress on a normal car would to power slide thru every corner.
One thing I am a big advocate of, is safety first! Yes it may cost more, but when you have a failure and are stranded, or have damaged your trailer, you would gladly go back and pay the additional money if it would undo what has just transpired. I know I would. I try to think long term when it comes to this stuff, but thats me.