wiixplorer passes ahbprot to whatever it launches just fine. you just have to install it as a channel / forwarder and put the ahbprot bit in the tmd. also, it is not HBC that has "bootmii@boot2 & nand backup" those are part of bootmii & backupmii which are different programs completely than HBC. they just happens to be written by the same people and are installed by the same installer.
wiixplorer still does not have the wiiload/usb gecko stuff that HBC does. nor does it have the ability to directly boot bootmii IOS ( isnt an easy thing to do, it just doesnt have the button to do it ).