We use a Croozer Kid For Two, and we love it. I replaced the tires recently, but badly: one twisted, making the wheel look like it was out-of-true -- to the extent people started stopping me to tell me my "wheel was buckled". The twist was easily fixed, but it got me thinking.
How would I true a rim from a two-wheeled trailer? My own jig assumes a through-axle, but the trailer uses cantilever axles.