I have a shell script that batch converts md to HTML. I know you asked for RTF but this will also work, or you could modify it to convert to another format. I use this to import to Notes, and have had good results with hundreds of files at a time. Notes will import HTML files.
You can download it here: https://drive.google.com/file/d/1RAtI3to2z__viuxhZnYECWinc8kKNl-9/view?usp=drivesdk - note that it requires Pandoc to work. It also adds the file name as the title of the text file, you could remove/comment out line 22 to prevent this. Unfortunately, there’s currently no support for images, this would need to be added.
It can be opened with any text editor so you can see the commands. You will need to make it executable (cd to the folder and then do chmod +x ./convert) and then copy it to the folder you want to convert, then run in terminal. It will make a new folder with the HTML files. Then, use import in Notes.
Actually apple note exports — I realize you want imports — will export Apple notes to md, but the filenames are often incorrect or without an .extension_name (ie png, jpg,pdf etc). I get mostly the correct file name without extension but sometimes filenames are constants like “Fallback.pdf” where the link should be to three separate pngs. odd. I think if you are using Obsidian for your notes with a lot of pictures, moving to apple notes will (currently) become a one way affair if you’re not minded to python script the return pathway.
Does that maintain the folder structure? I’ve put years work into the files and folder organization of my notes. I definitely cannot afford to lose it!
