No. Unfortunately that is not possible.

Automation is required to get info from the Dock about which tile the mouse is currently over, when the mouse leaves and enters the Dock and preform actions on application windows like focusing, hiding or closing a window.

Screen Recording is required to capture the preview images of each application.

Additionally Calendar permission is required to display the events of the day in the special Calendar preview.

Not without an update to the app but as long as the 3rd party app syncs with the System calendar then it will be easy to add in a future update.

Try restarting System Preferences and DockMate.

DockMate only shows windows that have an accessibility element. Some applications may draw their own custom window that is not reported to the system as a normal window. Unfortunately it is unlikely support for specific edge-cases will be added.

It's possible DockMate has lost the reference to that window or that the window can not perform that specific action to begin with. You might try restarting DockMate to see if the issue resolves itself.

When some windows are hidden the system will provide back only a blank image when DockMate tries to grab a screen capture of the window. When possible we try to show the last available screenshot of a window in this case.