[Buschel]

Yes, can be done. This is just a missing configuration with few lines of code.

Screenshots:
https://ibb.co/6n8sbKv -> Video > Files > played/unplayed video which are not in DB
https://ibb.co/m6W4c2r -> Video > Files > played video which is in DB
https://ibb.co/4JKFBT6 -> Music > Files > played/unplayed video which are in DB or not
https://ibb.co/X518hzr -> Music > Files > folder which hold an album which was played and is in DB
https://ibb.co/vs8yq07 -> Music > Files > song which were all played and are in DB

This is perfectly in line with some other work I had started months back to introduce a file icon during file browsing. The current way of showing the video/musc/picture icons in the File-view is a not correct.

Edit:
But there are complications. Kodi does not provide correct "thumbnail" image links for movies. This was changes years back and I need to use "art" in such. This is generally working fine, but I am quite sure I need to limit this to certain Kodi API versions. It is always a hassle to support many iOS, devices and Kodi servers. Let's see.

Screenshots:
https://ibb.co/N292HVC > requesting "thumbnail" from Kodi 19.5 
https://ibb.co/6g94C8r > requesting "art" from Kodi 19.5