notes on second screen and "destination with the same identifier" warnings

[u-fischer]

As has been noted in this tex.SX question https://tex.stackexchange.com/questions/350993/beamer-presentation-with-notes-navigation-does-not-work-properly-and-destinati notes on second screen leads to lots of "destination with the same identifier" warnings for page and navigation anchors.

beamer defines in beamerbasenavigation.sty a simplified version of \def\Hy@EveryPageAnchor which hardcodes the names of the anchors:

    \hyper@@anchor{Navigation\the\c@page}\relax%
    \hyper@@anchor{page.\the\c@page}\relax%

This means that it is impossible to manipulate the name of anchors by redefining e.g. \thepage. And as the code for notes on second screen contains \advance\c@page by-1\relax the destination anchors are no longer unique.

[cpitclaudel]

Would it be possible to make the definition of these anchors conditional, to avoid redefinition warnings?