With Tinderbox you can start on the Tinderbox side and “watch” a group of documents in a DEVONthink group.
Or, you can drag a file from DEVONthink to Tinderbox.
In both cases, Tinderbox creates a note linked to the DEVONthink document NOT for editing purposes. View only.
Of course, with this method you get all the cruft and a lifetime of head-scratching that goes with being a Tinderbox user.
Do not underestimate this part.
I love the concept of Tinderbox. I really want to be able to put it to work. The head-scratching gets me every time.
I have some Keyboard Maestro macros. One of them will copy the link of the current DT item, switch to MindNode and paste it as the node link.
In Devonthink, drag and drop a Markdown document into the DT Markdown editor for adding a link. Control-drag and drop (thanks, @BLUEFROG !) will insert a transclusion.
Transclusion to an external app might be a bit much, but if a click and drag from DT could carry the x-DEVONthink-item link, that would be a pretty cool thing.
In the meantime, copying the item link in DT and pasting into anything that can handle x-links seems to work fine. MindNode, OmniOutliner, Mellel, and Curio all seem to work.