Our plan is to implement an html script that handles drops like the Transport plugin. We won't have markup to configure it but will probably just read something off of the page for initial experiments. See About Transport Plugin
We will eventually write a drop handler in this Code plugin. Right now we just grab the endpoint url.
Here is the script that actually handles the drop and gets the work done. github
Then this is the Frame where the script shows its drop zone. Within this Frame the html script can open new pages in the lineup. This is a new feature of Frame plugin that has proven very useful. See About Frame Integrations
Drop an image url above. Try this page's flag.
See some favorite images. commons
The dropzone could be a collection of drop target icons for various transporters bundled together. google
Compare with this legacy transporter.