neoncube
neoncube would put significant load on the Memrise servers.
Would it be possible to have the extension distribute the payload and keep track of what courses' progress has already been downloaded (i.e. by assigning a working directory in its settings)? Max out at 10 courses per day could also e an option.
FWIW, I wouldn't mind having the add-on run in the background (even over several consecutive days if need be) while I'm working.
Also, you could also distrubute a max. amount of requests via your own server by providing "slots" (say, 50 concurrent users downloading their progress, others would have to wait). Just a few ideas - I know there might be quite a bit of work involved. :-)
I also can't quite imagine how much load it would mean to query the progress across 112 courses in my case. Can it really be all that much?