The recent "it" (is targeting) command changes have been reverted, and the "itm" (is targeting mob) command has been added instead. "it" will check for mobs and players outside your party, and "itm" will check for mobs only.
I've added support for checking hotbar slot 20 with the "ch" command (ch20) for the Korean client. I am unable to test if it works, however, so let me know.
These changes require Speeder version 149+.