If you want to make level cycling work properly, just make a jj2+ levellist, putting them in treasure mode. It only takes a few seconds. If you do this, you can also automatically make a zip file with all of the levels, AND include the tilesets. It couldn't be easier.

You'd probably have to make separate lists (or even separate j2o uploads) for the normal foo races and team foo races.

It's interesting that you mention unfinished races. As far as I remember, there weren't really that many unfinished ones (or at least, the only ones that got hosted were finished, and there were a whole lot of those). The main problem was that some of them were basically unwinnable due to what I will politely refer to here as "design issues".

In any case I'd also be interested in seeing this on J2O, since I remember making two or three of them semi-anonymously, and I've totally forgotten the filenames now.