Originally Posted by Sith Holocron
An idea . . . have be enter-able only after the Temple Rooftop showdown.
Not necessarily. It always seemed far fetched for me that simply undertaking one task - invading the other Rakatan base - would convince the One/the Elders of your motives and thereby they would open the temple door for you. Perhaps this ship mod can add an extra mission that's crucial towards gaining the Rakatan trust, and only afterwards would you have access to the temple.
Since at this point you know you're Revan, an idea for the quest could surround Mandalorian Crusaders who retreated during the Mandalorian Wars. Afterall, Mandalorians were not that significant in the story - in terms of actual presence - so this mission could establish some background about them, and possibly even about Revan. This would also explain why the Mandalorians - of all the places - are on the Unknown World.