All my photos are mastered in my DAM/editing software - Capture One: I do all my photo edits and touch ups here, and also adding all IPTC meta data.
I have now structured the genealogy photo folders in my Capture One library to match the structure in RootsMagic.
So now I just need to export Capture One images to TIF using the same folder structure as the source, and this becomes my RootsMagic media folder!
You are not the only RM user who uses some sort of content management software to manage their image files. It's obviously a very powerful way to work, but so far I have not chosen to go that route. Even though I'm pretty high tech in general, I seem to go the low tech route for my image files. For example, I annotate my photos of things like people and places (e.g., the old farm house) by making a second copy of the photo, adding white space, and placing the text for the annotation in the added white space. My low tech tool for doing so is Microsoft Paint. It's like writing captions on the back of an old photograph except adding white space and adding the captions to the front. My "captions" just become a bunch of pixels and are not searchable or manageable. But my "captions" are not likely to get lost. I do try to include enough information in my multimedia file names to make them easily searchable and sortable and that sort of thing.
I have tried using GIMP instead of Microsoft Paint because GIMP supports layers and my added "caption" can be a text layer that is really text and not just a bunch of pixels. But using GIMP just seems to add unnecessary complication and time and effort to the process as compared to just using Paint.
For whatever reason, I have a great distrust for things like EXIF data and IPTC data. They seem to me to be hard to manage. With most software, they seem hard to see, hard to search, hard to print, and that sort of thing. And they seem very fragile. The data seems to be easily become lost when I copy or edit image files with simple tools. The EXIF data really isn't very meaningful anyway except in the context of original photographs made with a digital camera. EXIF data from a digital camera can be important, but any EXIF data from a scanner seems quite irrelevant. However, the IPTC data (captions, etc.) is not the sort of thing you want to be easily lost.
It's not IPTC data exactly, but RM is a guilty party that once upon a time lost a lot of captions for me. RM originally supported tagging media only from the item to which the media was tagged. For example, tags for people and events could only be created from the Edit Person screen. Tags for Sources and Citations could only be created from the Edit Citation screen, etc. Many of my captions were for family photos and my caption for John Doe might say some like "John Doe, front row, second from left" and my caption for his older sister Jane Doe might say something like "Jane Doe, back row, third from right". In other words, the exact same photo could have a different caption depending upon the context in which it appeared. Then RM added the ability to tag from the Media Gallery and from Media Albums associated with individual items in RM such as a person. In the process of making this change, RM limited each photo to a single caption and I lost most of my captions in RM. Fool me once, shame on you. Fool me twice, shame on me. So I'm never going to trust RM again to be the keeper of my captions. And I'm not sure I really trust the IPTC data not to get lost by other means. And if I used Capture One to manage my photos and my captions, I'm not sure that I would really trust the data not to get lost when it is passed along to my children and grandchildren.
Despite my misgivings about IPTC data being the "permanent record" for captioning, it does make sense to me for RM to support it as a source for captions. It's too bad that it doesn't However (and if I understand the IPTC correctly), that would mean that each photo (including group photos) could only have one caption. When I "caption" my photos in my low tech way using Microsoft Paint, a group photo obviously only has one caption and the caption lists everybody in the photo. But a group photo is often the only photo I have of somebody. For example, a 1925 photo of my mother's family with 15 people in the photo is the only photo I have of her grandparents. So I have used Microsoft Paint to copy and paste them out of the original photo and into an image of their own, and this image has its own low tech "caption" added by Microsoft Paint.
Anybody who has read my posts through the years has probably picked up on fact that I have a background in math, science, and computer science. I basically did IT support for a living at colleges and universities, and I regularly taught a single math or computer science class on an adjunct basis although being a professor was never my official day job. As such, I worked extensively with libraries and librarians. In fact, at the last place I worked before retirement the library was a part of the IT department. I had numerous discussions about these kinds of issues through the years with the librarians, and they were universally in the "content management software" camp as the way to manage content. They would have loved your Capture One software. In fact, a library catalog is just a piece of content management software except that it is managing books instead of photos. But there is an institutional support there with a library. When a librarian retires, the library catalog is not going away. When the software managing the library catalog is replaced by a different piece of software, the library catalog will be converted to the new software and will not go away. But when I pass along my genealogical data to my kids and grandkids, I can't see the "institutional support" being there to preserve my work in any way other than low tech means.