The TL of a planet, isnt strictly related to the education and experience of the sophonts there. The TL is a measure of what the planet economy can produce and maintain domestically. There is also no strict corelation bbetween a planet TL and starport quality. There is also very little in the means of a 'prime directive'. So low TL worlds can and do interact with higher TL worlds.
As best I can determine, the TL of a world means nothing. It tells you what TL is "commonly available" but can average up or down by 2 TLs. Oh, and they have a starport so you can find Plasma weapons and grav tanks there too. Oh, but you can't get stuff fixed at that planet unless it is of the right TLs, nope. Not true either. Basically, TL is so vague as to mean nothing, same as every other f*cking stat I discuss on here. This aggravates Me to no end. Pop means nothing. Law Level means nothing. Size means nothing. Seriously guys?
This means sophonts from low TL worlds can work as a mechanic at the starport, even though there home is a earthen mound. This means that sophont can go off world and get educated at a subsector capital and come back to their low TL world. This means that low TL sophonts can get drafted into the Merchant Marines. This means that sophont in low TL world can be taught how a high TL system works, even if they dont interact much with them.
The Imperium has a mandate to raise the TL of its client states, so its interested and invested in do that.
Onon. The planet right next to Capital, TL-7 Class-D starport, but otherwise ripe to be a Ht In world. If they can't upgrade a world right next the capital, that they have had for over 1,000 years, then I am not sure that is actually their intent. Even in just Sylean space, you have a bunch of TL 7s 8s, some 6s. They have controlled that space longer than there has been a 3I.
If the question was really about a sheltered low TL sophont, who for whatever reason, never seen any advance piece of technology, and its all of a out of context problem.
Then the answer is, it takes a while.
I am saying how is there no rule in Traveller for attempting to use technology outside of the TL of your education? I show a laser pistol to a Roman Centurion in Traveller, and he may know how to shoot it, having seen others do it, but his Mechanic skill should have some serious penalties to it, if he wants to repair the laser pistol. Like making it an Impossible Task.
They never grow a deeper understanding how it works.
BBbut they can bbe taught how to do operations, and how do things in rhote. That doesnt require deeper understanding why its done that way.
So, in other words, they can be trained like monkeys, but not learn like humans, unless training starts in childhood or attend some kind of a school to teach the technology, in which case, they would not be a TL-1 person.