Gogo select more commands?

The game compile everyone's commands, excluding guests and dead Shadow then remove duplicates. That is how Gogo's skill selection menu is build in vanilla. Modifying this behavior will require an ASM hack (see $C35DC8 in the $C3 Compendium). I don't recall if there is scrolling or extra room in Gogo's menu so that is to take into consideration. You may need to expand or modify the $CFFE00 command properties table to support you extra command too. I dunno if it has entries for commands gogo wouldn't normally have..