Did Wakanda reverse engineer alien technology?
 

As we can see on this page by Jack Kirby, the pieces being collected appear to be some kind of technology. It seems as if Kirby intended the Vibranium meteor to not be a meteor at all, but rather a crashed alien ship mistaken for a meteor. Now I realise the idea that the Wakandans were always super duper smart scientists who put everyone else to shame for centuries was a retcon, clearly T'Challa did not have to study abroad if that was always the intention, but they were always depicted as being ahead. And with or without the retcon, it still explains why they are so far ahead.

Now if anyone could actually identify which alien civilization they copied their tech from...

The in-story explanation doesn't have to be alien tech. It could just as easily have been a large meteor made of the alloy that seeded the mountain with it.

Any further real life explanation about how a "it can't be a meteor because a meteor of that sized would have killed everyone" is foolish because
A) it's a comic book
and
B) even that could be "scienced fictioned out" in the story

And so it's more likely that it was a meteor of raw material than a spacecraft that was so big that it seeded a mountain with pure vibranium forever.

As a matter of fact it's less likely that it was a spacecraft because if it was forged vibranium then it would'n't have likely be unrecognizably destroyed.

It didn't have to be a spacecraft to explain the material, no. A meteor is a perfectly fine explaination for the material itself, the question is more about how they learned to use it, for which a spacecraft would help explain it.

Human beings have made use of copper for at least 9000 years but electrical engineering wasn't really a thing until 200 years ago. If they had samples of vibranium technology to study, that would make the process of figuring out how to make something useful out of it much easier.

Well they learned to use it by any real sociological explanation for any society - location during development leads to specialization in things regarding the immediate environment.

e.g., in-story vibranium was pretty much only found in Wakanda, and so while other parts of the world were toying around with copper or forging steel, Wakandans were toying around with vibranium and it evolved from there. And because it's an "advanced fictional" metal, it was then a gateway to technological uses that could surpass other civilizations that had their own, different gateways. For example, maybe vibranium is super conductive on it's own merits and led the civilization to develop electrical engineering more quickly.

When you are a civilization built on a shoreline, you had a greater navy than other nations. When you are a civilization built near limestone deposits, you had quarries and stone architecture before other nations. When you are a civilization built at the base of a precious metals site, you have mining before other nations.

They didn't need vibranium technology. They only needed the vibranium.