You raise a good point...
In my case, I would have to quickly learn everything I do not know about Sunset... something that may be easy to do if I can use her geod´s power [but it also means I would have to be VERY CAREFULL until I got enough knowledge about how every other person/pony thinks about her].
Given that her geod "dissapears" when Sunset goes to Equestria, it may mean using its power is not a posibility while on pony land [so I would had to find a good reason/excuse to bring Twilight, Spike The Dragon & Starlight to Pedestria (CHS); to "scan" their memories].
Ce