You can set the global preferences and store the values in the Value property for all users. All users can access the value, but only administrators can update it. Any JSON can be stored in the property, but it is returned as a string.
You can set the global references using the following example POST:
. . /api/v1/User/GlobalPreferences
With this Payload:
{"Value":"GlobalPreferencesToStore"}
You can also get the global preferences using the following example GET:
. . /api/v1/$metadata#User/GlobalPreferences/$entity