We have a solution that utilizes both AsoManager and CredentialStore controls and I know that the AsoManager file is stored in the Roaming folder as ASO.db. But where is the files for CredentialStore stored?
Did you alter the Location property of the CredentialStore component? If so, that would explain why it is elsewhere. If you did not alter it and the property is set to "%AppData%", then you likely haven't yet saved a credential. The file and directory are not created until a credential is saved.
ASO Manager is the newest credential component. It comes with a built-in UI and can be used to login to certain adapters without the need to create automations. The credentials are stored slightly differently on the machine, but are otherwise encrypted the same.
The CredentialStore component is the original means we created for storing credentials and requires you to create a UI to collect them from the user. You would also need to retrieve them from the component for use in your automations.
You may use either component depending on your needs. Look in the Help documentation for more specific details as there are some examples in there for each.