Before updating to 3.8 I used to be able to drag and drop an image into TaskPaper to insert its pathname.
As in: 
I don’t seem to be able to do that anymore.
Currently running TaskPaper Version 3.8 (328) on macOS High Sierra.
I think this is fixed in latest preview release:
Assuming I get no major bug reports from that preview I’ll probably make it the official release in a day or two.
Gotcha, thanks.