Hi Tony,
Personally I have never liked the idea of these.
I was once at a show admiring a superb GWR layout. All loco were kit built and I had a discussion with the owner about kit building. The first warning he gave was not to use friction-fit wheels. He had constructed all his loco with Gibson wheels and over time all had moved on their axles. He was slowly changing to Markits.
I am aware of some who have had success with the introduction of a pin but this seemed fiddly. Much prefer the Romford nut!
Regards,
Terry