Trying to find most "soft" way to alter data for already existing checkbox field. Aiming to change the labels value for on/off but updating them from UI or programatically is not working out, field_config contains proper allowed values array. Im not sure where else too look, on node view Im still seeing 0/1 values event though I changed the on/off values to string representations. I know I can do it on node view alter but I want more general solution, also deleting the field base and recreating is not an option here. Any hints?
Solution was to reexport into features field_base and field_instance proper labels, then to make sure field_config and field_instance_config blobs are properly updated. I used update hooks to resave the fields with proper info, I loaded them with field_info_field, set the required properties and the used field_update_field. Also field config from list_key must be changed to list_default.