... solved! (I swear it's like walking into someone's office to explain a problem, and then minutes later it gets solved in the telling ...)

I had my local firewall enabled, and so I had to temporarily enable ftp access (which of course allows access to various ftp ports INBOUND - which the empeg would need, even though I don't allow inbound ftp to my Mac).

Maybe if I had used PASV mode it wouldn't have mattered? Eh ... it worked in any case. Hijack is now updated. Yay!