You can create whatever palettes, folders, etc that you want in the View Map. If the elements in the 'palette' (which might be hotlinked from elsewhere) are not to appear in schedules, then just assign all of them a special ID prefix/suffix/etc so that you can filter them out.
(The Project Map is for view points, which are quite different.)
Cheers,
Karl
One of the forum moderators
AC 27 USA and earlier • macOS Ventura 13.6.9, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB