Stress projection on nodes

In one of the ( tutorials by Claws )

He gives the following warning:
"Notes regarding this study

It is always recommended to extract the nummerical values of the EQUI_ELGA_SIGM field and print it to the .resu file, rather than relying on Salomés (or other) graphical representation of e.g. Von Mises stress - this has to do with the way the values are extrapolated from the Gauss points onto the nodes when displaying EQUI_NOEU_SIGM. This extrapolation results in inaccurate results, i.e. too high of a value or even negative values. This has been discussed several times on the Code_Aster forum. ELGA fields cannot yet be projected back to a linear mesh"

Is this warning still in place? If so, what is exactly the problem?