DH & I are going through the same process with our two 'bents and a new Neon.
Essentially, we are getting nowhere. My research indicates that the reason a lot of trailers bounce is that they are meant to haul heavier loads than our bikes, so the suspension is too stiff. Makes sense.
I'm about half ready to take my bike & some specs to a local welding shop & have a bike trailer made the way I want it made.
It might cost a bit, but maybe less than the pre-fab jobs, and if it's wrong, I'll know who to blame.
Sadly, this probably won't happen until that imaginary million dollars falls into my lap. **Sigh**
Give big space to the festive dog that make sport in the roadway. Avoid entanglement with your wheel spoke.
(Sign in Japan)
1978 Raleigh Gran Prix
2003 EZ Sport AX