I'm not sure how much (code-wise) he changed for the FTP server. I can't find any source code.
I haven't been in the scene since v2.3's release - and now I've just come back to release the (probably final) version.
Version 3.0 fixes the multiple connection problem. There aren't any hard limits to the transfer/connection code, so it's all dependent on hardware.
I would like a comparison test to be done between the stable v3.0 and mM ftp. Tests should include: single-file transfer, multiple (large) file (simultaneous connections) transfer, multiple (small) file (simultaneous connections) transfer. As well as a stress test over a large number of simultaneous connections.