The only way I know of to edit contents in .dot files is via Git and using the app Working Copy. With it you can see .dotfiles and .dotfolders. You can also set Working Copy to “sync folder” to a folder of your choice. Sadly, as you say, there is no way to actually view or select a .dotfolder in the “Files” app, so you would have to “Sync Folder” with a higher level folder.
All of this might be overkill, but just saying I was also looking for ways to edit .dotfiles (on a completely unrelated matter to Obsidian) and concluded Working Copy seems to be the only app in the iOS/iPadOS universe who have cracked the code of syncing the contents of two folders much like a symbolic link.