Multi-value checkboxes/select support?

John, yes its a limitation of field storage. There is no current solution for this to be addressed in the future since we are dealing with a single column in the table to store the value. Anything other than storing in a separate table would lead to a workaround like storing a string with separators or using the map object to serialize the data. Neither would lead to a desirable experience of preserving and rendering the data for other uses. I think we have to think as custom fields as single value sub fields only for now. If you or someone else wants to propose a separate table solution that perhaps extends current fields to support multi-value, feel free to provide a patch and reopen this.