My vague understanding of the issue is that Logos doesn't allow for inserting pictures into notes because this would take up significantly more space on their servers.
What about local sync options? For instance, most apps nowadays sync between user devices and often allow use of services like iCloud or OneDrive to accomplish this. My understanding is that the app developer is not hosting or storing any of the user's data--it is being stored on the user's own cloud storage service (e.g., OneDrive).
This seems so obvious that perhaps it's already been suggested. Maybe it's difficult to have two syncing systems in the program (one with Logos' servers and another with the user's chosen cloud service)?
If I remember correctly, image files in notes has been an topic of a lot of discussion, but I'm only an itinerant forum reader/poster so I can't keep up with the current state of things.