I became aware of the recommendation not to use 1st Radius curves shortly after I had purchased some. However, whilst I tend to build a similar type of layout on a piece of 8' x 4' Sundeala board each time I put it down, I am sure that it is never exactly
the same. I do not fasten the track down and I have lots of standard Hornby points (R8072 & R8073, which I think are also 1st Radius). I have no flexi track. All my track is Hornby.
I tend to build 4 ovals (1st to 4th Radius) with points to get from one
oval to the next and with some sidings in the middle.
I run Class 08, Class 20, Class 37, Class 47, a Smokey Joe, and a Duchess of Gloucester.
In my experience and maybe I am just fortunate but the only loco of mine that will not successfully negotiate
1st Radius is the Duchess of Gloucester (R2386).
It is DCC, operated from an Elite and RailMaster and incidentally, I only use one power connection which is on the 4th Radius oval.