hey, nevertheless i will move this to bricked section, just because i have the exact same issue, and maybe someone experienced can help us
So you have a booting and returning loop set in priiloader, as you figured: synching withing the loader or priiloader does not work. we need to get to the hbc or sysmenu somehow.
I thought of cboot2 to load a hbc forwarder (needs bootmii as boot2 installed obviously), found on another wii you can synch inside hbc.
OR: just use a GC controller to adjust priiloader hacks again, i have none yet ..., so you would just revert the boot and return settings to sysmenu.
(guess there exist no forwarder for the sysmenu hehe, or ?)