I have been increasingly using Drafts for various aspects of my notes/writing but have been challenged by the effort needed to add images to Markdown in Drafts and for the image hosting to remain usable in both DT3 and DTTG on my iPhone.
With some help from the Drafts forum, I was able to get a workflow going with iCloud on the Mac. I was then able to apply that concept to Dropbox, which makes it easier to view the resulting images on iPhone Drafts and DTTG.
Of course once the text and Markdown images are visible inside DT3, you can easily convert that to HTML or Rich Text; thus for me at least, the ability to easily include images in Drafts is very notable in terms of being able to use Drafts as an initial step in virtually any sort of information gathering or first-draft writing that I need.
To use this first install the Shortcut on Mac shortcuts. Then add the Drafts action called Linked Clipboard Item. Before running it, capture an image to your clipboard. Then run the Drafts action; it will call the Shortcut to save the clipboard to iCloud or Dropbox and then it will insert into Drafts a Markdown link to the new image. The resulting iCloud-based markdown image will then also work when the markdown link is sent to Devonthink on the Mac. If you use the Dropbox version then the resulting Dropbox-based markdown image will work on both iPhone Drafts and iPhone DTTG.
The links for the shortcut and Drafts action using iCloud image hosting are here:
The links for the shortcut and Drafts action using Dropbox image hosting are here:
A bit more background here: