courtneyjordan → created an issue.
I have an update with a work around. You can ethier remove the field and recreate it adding the new items to your list and keeping the machine names with their boolean values, keep in mind you'd need to do this for every instance you'd need to add a new item. If you have a time constraint and you need to make a quick change without mucking up the code this works.
-however-
It's best to recreate the list using a meaningful string of text for the machine name indicating the items action. The you'd never have to worry about the boolean value of 0 impacting future updates to your list.
These solutions will work but keep in mind if you plan to use boolean values refrain from using 0 as it equals null and that can cause breakage in this case. Hope this helps!
I'm encountering this issue as well on 10.2.6
The value field remains disabled, displaying a 0 value.
The list field i'm working on requires new field options and i'm currently unable to do that and not sure what to do.