Issues with Exclude People Option in Clay and Apollo Integration

Problem - Exclude people option not working in the following scenarios:

1.
Clay people search - While adding new people, the option available is only to exclude from the table where there is direct source, I can not select my own database
2.
Apollo people search - While adding new people, there is no option to exclude from already saved people / lists (in Clay table or within Apollo as well)

Taking help from developers, they said even HTTP API won't exclude within the above cases as there is no option for excluding. How to implement this?