I've always played it such that tech level was what was "commonly available and/or able to be manufactured", rather than it being a hard number where nothing higher tech was available. The Imperium is/was a start spanning empire where interstellar travel was very common. Sure there were backwater areas and worlds that were "off limits", but how else do you explain a world that has thousands of inhabitants is at TL6 with a very thin, tainted atmosphere? They import the goods necessary to survive.
Thus, in the TNE setting, a world might be TL 8, but they may have everything from TL 8 to TL 15 available in terms of merchandise. The TL 12 stuff might come from a nearby TL 12 world (along with some TL 11 items manufactured as that world progressed--think old computers that people in the West treat as near junk, but to someone in Ethiopia they are super powerful PCs), TL 13-15 stuff would naturally be salvaged relic equipment that would be expensive and finding spare parts could be challenging. Local people would of course be making TL 8 stuff, and depending on what is was (say farm equipment or tools) it would be "good, sturdy gear". Not everything needs to be the latest and greatest technology--indeed locals may even have a preference for the lower tech stuff.
So if I were on Oriflamme, I'd expect that most things would be TL 8, in some tech areas there was be a fair amount of TL 11-12 imported gear, especially electronics (light weight, easy to ship in bulk, ask the Japanese...). But if "you know a guy who knows a guy", maybe you can get hold of a precious TL 14 Solomani holo projector. The rest is up to your imagination and how you "make it work" for the game you are running.
Thus, in the TNE setting, a world might be TL 8, but they may have everything from TL 8 to TL 15 available in terms of merchandise. The TL 12 stuff might come from a nearby TL 12 world (along with some TL 11 items manufactured as that world progressed--think old computers that people in the West treat as near junk, but to someone in Ethiopia they are super powerful PCs), TL 13-15 stuff would naturally be salvaged relic equipment that would be expensive and finding spare parts could be challenging. Local people would of course be making TL 8 stuff, and depending on what is was (say farm equipment or tools) it would be "good, sturdy gear". Not everything needs to be the latest and greatest technology--indeed locals may even have a preference for the lower tech stuff.
So if I were on Oriflamme, I'd expect that most things would be TL 8, in some tech areas there was be a fair amount of TL 11-12 imported gear, especially electronics (light weight, easy to ship in bulk, ask the Japanese...). But if "you know a guy who knows a guy", maybe you can get hold of a precious TL 14 Solomani holo projector. The rest is up to your imagination and how you "make it work" for the game you are running.