you dont need to because your channel list will still be there after loading patch 142p
i have tried it but found too many bugs so went back to 139p again .
You dont need to factory reset thats the only way your current channel list will get deleted ,
but you can backup your list if u desire its very simple just insert usb pen
Goto Menu Button on Remote > USB/External Device > FTP
then Info Button > Upload channel data and ok button
job is completed : ))
Good luck : )