Currently the following tests are tagged with assumes_balancer_off:

• query_settings_index_application_aggregate.js

• query_settings_index_application_find.js

• query_settings_index_application_distinct.js

This is presumably due to the plan cache checks included in the tests. We could gain some additional coverage by replacing the tags with more fine-grained TestData.runningWithBalancer based exclusions. This flag is only set to true on balancer-enabled suites, and could be used as an early exit in QuerySettingsIndexHintsTests.assertQuerySettingsInCacheForCommand()