It is described the effect of plasma operations producing low particle recycling from the vessel walls during the L-mode (prelude) phase, on core confinement in the H-mode (main heating) phase. Available data of experiments of JET are considered, aimed at approaching fully non-inductive ITER-relevant conditions. The relatively high electron temperature produced at the edge by the initial Dα level condition, results favouring the build-up of high normalised β (βN) regimes, in which the confinement is improved in large plasma volume. Modelling of turbulence of the edge, transport, stability and current profile evolution helps interpreting this complex phenomenology, indicating a link between the values at the edge of electron temperature, bootstrap current density and local magnetic shear and the confinement in the core. Such link would favour these regimes to be self-sustained in the time.