How does the setting handle development of tech outside its usual bounds? For example, can a brilliant scientist PC hope to develop FTL comms, an alternate FTL (such as one that doesn't require massive sections of the ship devoted to fuel), transporter/teleportation technology, energy-to-matter transformation (replicators)replicator, time travel, or mind/body transfers?
Having no FTL comms is kind if a hard line for the traveller universe. If the speed of communication is limited to the speed of travel, the. You get a more 18th century Age Of Sail/far-flung empire vibe. A universe with FTL comms would be more like Star Trek or Star Wars.
Of course, you can introduce FTL comms, but you have to rework the universe. Taking into account the new parameters. The 3rd Imperium with FTL Comms would have a stronger central government since the Emperor could get news from all over the Imperium very quickly and dispatch agents or the military to handle the job.
But using the basic traveller rules, you could definitely build that universe. Some of the official Traveller adventures would probably still work, you’d just have to do some modding.