There is a new plugin to be used with MarginNote. With an URL schema like:
x-devonthink://createMarkdown?title={{notebookTitle}}+{{start_page}}_{{end_page}}&text={{allText_p}}, {{link}}&tags={{tag}}
I was able to create new entries in DevonThink from selected cards in MarginNote.
So I’m looking for the option to create a new note in TBX using a URL scheme. This would be the missing link between MN and TBX… 
@webline any progress on this one?
I would be inclined to do the creation in a post-import stamp; the create() operator is really quite good, and I expect this won’t be difficult.
The stamp might be invoked by an OnAdd operator if you need to do this often.
But I’m happy to look at the implementation if it’s really going to be useful.
The original post in this thread (2022) references an MN plugin for MarginNote 3 (MN3). While MN 3 is still working, the current version is MarginNote 4 (MN4). There have been several releases since 2022 of both MN3 and MN4. I have both MN3 and MN4 updated on my machine with current versions. The referenced plugin from the original post above now throws off this error in both MN3 and MN4.
I dropped MN 3 from the list of apps I use - so I didn’t even notice that a new version is out. The support for MN 3 was awful - but I will look into the new version and if there is an improvement I will also look again in connecting it to TBX.