Do you think there is an episode or episodes when separating the ship could have solved the problem they were facing? Maybe the writers kind of forgot or ignored the possibility to separate the ship to keep the plot exciting? One of those episodes could be 'The Enemy', send the stardrive section to meet the Romulan ship to help save the life of the Romulan officer they found and the saucer section could stay in orbit of the planet where Geordi was on. What about 'Schisms'? There was a weird dimensional thing going on in one of the cargo bays. Get everybody into the part of the ship that is safe and then separate? Or was that dimensional thing affecting both parts of the ship? The separation is a nice feature but it might create problems for the writers in some cases. Can you think of other examples?