Hmm, I don't really see why Implicit should have lost the race, seems to me like a taste thing?
But still, the only way to turn off secure transfers is to use Auth SSL/TLS, and then turn it off. Why not be able to turn it off with Implicit SSL also?
Which ftp servers allow PROT C during Implicit SSL connections? At the time of implementation I was unable to find any, the servers I did test specifically disallowed it.