[un_pogaz]

The new Mark books button, with the improvement support of the named mark, is realy a super nice addition.
But a big User button is not probably the best. Okays, this is nice in the context menu, but on the toolbar... that seems over huge.

I suggest to add this button in the "Search" area, which seems logical to me because it is incredibly in this case, besides, there are already quick search tools integrated.
Of course, this button can be shown/hidden in the same way as the "Show toggle button to switch display search".
We still have the button, but smaller and more discreet.