You can disable the new 'saved search' functionality that was introduced in version 14.1 by typing these commands to edit the nx.env and template files:
pdm_options_mgr -c -s DISABLE_SAVED_SEARCHES -v 1 -a pdm_option.inst
pdm_options_mgr -c -s DISABLE_SAVED_SEARCHES -v 1 -a pdm_option.inst -t
But if you're having performance issues with existing saved searches that were created, there doesn't seem to be a good way to remove them. Inactivating the saved search stored queries does not seem to stop them from working, and resetting everyone's scoreboard and making them manually re-add their legitimate stored queries back to their scoreboard is extremely disruptive. There should be a mechanism in place for an Administrator to be able to deactivate one (or all) saved searches via the interface.