The only thing I can come up with is switch to non-portable version and symlink the .ini settings to Dropbox, but that's a bit hacky and I have to set it up on every new PC I use. I wish I could install the proper shell association even in portable mode.
Do you have any solutions to how I might enable backgrounding using D&D / temporary download mode? Is this considered a bug, or is it by design?
Gonna stick with WinSCP either way, having encrypted passwords and a "please overwrite all" dialog was the reason I left Filezilla. And portable mode, of course.