In the GUI version of the YaST2 package manager (sw_single), selecting a
repository from the "Repositories" tab shows a "Switch system packages to the
versions in this repository" command.  This command is missing from the ncurses
UI.  (That is, if you select Filter->Repositories and select a repository, you
get a table of packages from that repository, but no way of switching all
packages to that repository.)

Though switching packages can also be accomplished using zypper on the command
line (zypper dup --from [repository]), it would help, for consistency's sake,
if the ncurses package manager could also do this.  This way, when writing
instructions for people, it's not necessary to give two different
vendor-switching workflows, depending on what UI they are using.