I’m still trying to understand how you want it to work. So let’s pretend you don’t have any media files in RM yet and let’s pretend your media files are poorly organized and are scattered every which way on both your C: drive and your D: drive. You can still link all your media files into RM. You simply link each of them into RM one at a time. I’m not recommending such disorganization. I’m just trying to explain how RM works for media files.
RM does not store any media files. Instead, it only links to where the media files are already stored. Also, RM has two kinds of links for media files. The first kind of links are actually called links. They link from RM to where the media files are actually stored on disk. There is a separate link for each media file. So if your media files actually are well organized, it’s not like you can tell RM the name of a folder where all your media are stored and all your media files are magically linked into RM. You still have to link them into RM one file at a time. Well, there is a way to link more than one at a time, but let’s start with the notion of one file linked at a time.
The second kind of links are called tags rather than links. The tags are used to link media files to items to items in RM such as people, events, and citations So for example to link an image of a birth certificate to a birth event, two links are required. First, the image of the birth certificate has to be linked into RM. Then, the image of the birth certificate has to be tagged to the relevant birth event. As the user, you can create both the link and the tag at the same time. Or you can create the link now and create the tag later.
Also, single media file can have multiple tags. For example, you might link a photo of a grave marker into RM, and then tag it to the birth fact for a person, to the death fact for the person, and to the burial fact for the person. That’s because the same photo would include birth, death, and burial information. So in this case, there would be one link for the media file and three tags. Another variation on the same theme is that you might link the same photo of a grave marker into RM and the tag the photo to a citation. Then, it would be the citation that is attached to the birth fact, the the death fact, and to the burial fact and the photo would be tagged only to the citation.
As I hinted previously, it is possible to link a bunch of media files in bulk into RM. The procedure is to go to Windows File Explorer or to Finder on a Mac, to highlight all the files in the folder, and then drag and drop them into RM. This is not actually dragging and dropping the files anywhere. They are still in the folders where they already were and they are not copied into RM. Instead, they are just linked into RM. What the drag and drop procedure is buying you is to link a bunch of files into RM all at the same time.
But none of the files so dragged and dropped will have any tags. They will be linked into RM, but they will will not be tagged to any people or events or citations in RM. Those tags will still have to be added one at a time.
Also, if you drag and drop all the files in a folder into RM and then add new files to that folder, the newly added files will not be linked into RM automatically. You still have to go back and link them in. In other words, it is not a folder that is being linked into RM. It is still the individual files that are being linked in. The drag and drop serves only to bulk add a bunch of individual links, all in one go. It doesn’t take care of adding the tags
Some users prefer to do the drag and drop to bulk add the links, and then to add the tags one at a time as a separate operation. But because for one file you can add the link and the tag all at the same time, some users prefer to do it that way and they don’t do the drag and drop to bulk add a bunch of links all at the same time. Because of the need to add tags one at a time, there will always be an element of “one at a time” processing for media files, no matter how you choose to do it.
I don’t know how much this helps answer your questions, but it’s my best explanation of how media files work in RM. You can’t just tell RM which folder and subfolders contains your media files, and poof! - the files are all linked into RM. You really do have to link the files into RM one at a time or in bulk, and then you have to tag them one at a time. And you are always working with linking and tagging files. You are never really working with linking and tagging folders - even if the files are well organized into folders and subfolders.