a stable version (7.1) was just released today :P
$chr() and $asc() still reflect the range of characters mIRC uses internally except instead of the 256 code point range of old (or 255 if you discard CHR 0) they now support a 65536 character range. Unicode outside of this range are formed using pairs of these characters, so $asc() and $chr() cannot comfortably handle them