We don't have that option, and I'm not sure if it's something we'd add. The status import from Facebook doesn't have a link associated with it, so there's no way to do a 'read more' with a link to the actual post. If we were to truncate the update then there wouldn't be any easy way for the viewer to see the full update.
Can you tell me if a user could add a status update to JomSocial normally that is of similar length? They may not do it, but if it's possible, then this would probably be a better suggestion to the JomSocial. They could add a way to collapse or expand really long status updates. That would have the benefit of working with all posts regardless of whether they come directly from JomSocial or made through a social network.
Thanks,
Alex