X-Chat, to my knowledge, is Unix/Linux based/ported, not Windows. mIRC is Windows based/ported, so it has to live with the limitations that are in Windows. As I said, I don't know if this is a Windows limitation or not, and I emphasized the word usually for the same reason, imo, that you emphasized the word legal in your original post.
I'm sorry if you took my comment to mean everything, as I didn't mean it that way, and if I had meant it that way, then I would've used the word everything.
That being said, if Khaled can and is willing to allow 4G+ transfers, more power to him and everyone that would like this.. and I am now finished with this topic.