Is there any way to remove the cached attachments from Mailspring?

Mailspring seems to store email attachments under (in Linux, Debian) ~/.config/Mailspring/files. It seems that files stay there even after emails are deleted and also after using “Reset Cache” under the “Local Data” section in the “General” tab of the Preferences.

Is there a way to remove the unnecessary files from within Mailspring?

Extra question: Wouldn’t this be the desired behavior of the Local Data/Reset Cache option?