[dmdsoftware]

Can I ask, where are the resume points stored?

It actually depends.

If you use read-only authorization, watched status and resume point is stored in your local KODI db, same as for any local media file.

If you use read-write authorization, in addition to storing locally in KODI db, playback count + watched status and resume point is stored as an attribute for the media file in your Google Drive account. So, if you playback on another device with the plugin, the watched status and resume point will instantly be shown. You'll even retrieve these on the other device if it is using a read-only authorization (you just won't be able to update the status or resume point).

A good note though: Because of limitations in local KODI db, the same media file shown in different folders or from search results will have different watch and resume points. If you watch a video from the search results page, if you playback from browsing for the video from it's folder, it won't have the same resume point as when you played it from the search results page. If you access it from search results page again, it will have the previous resume point. This limitation doesn't exist if you use read-write authorization, and let the plugin store the information in your Google Drive account.