My big example is Nevada during the gold and silver rush, where luxuries and tech hardly seen in NYC or London were routinely shipped to a remote arid mining district.
That's a frontier thing.
I love the scene from Tombstone where Doc referred to Tombstone as "just another mining camp" and Behan commented something akin to "Oh really? Dressing awfully tony for a mining camp. We'll be as big as San Francisco in a few years." Then there's the gun fight in the street. "Very cosmopolitan" from Doc.
Within a few year, Tombstone would be dying. These are some of those 10, 20, 30 year anomalies. Temporary civilization.
I think this would impact the spread of "ubiquitous technology" across an Imperium at the "speed of travel".
Indeed, to a point. But, again, we're talking 100's of years. Yea, TL-15 may be "only" 100 years old, but -14 has been around a lot longer.
Civilizations are created, rise, dominate, stagnate, and die in that much time. TL-12 is older than the Imperium, which "dies" in, what, 1120, 1130? From the Rebellion, virus, et al?
But travel is cheap, energy is free, and capital is not patient and willing to fill any vacuum opportunity provides.
We can point to things like North Korea and talk about limitations and protections and boycotts. But what's NK going to look like in 100 years? Who can say. Folks will say the same thing about the US. But I bet, barring calamity, I bet one thing NK and US won't be is "lower tech" than they are today. Especially when the galaxy is at your door and 2 weeks away from anything.