Unlike the last variant, the first two imply there was some quantity of work and it was all completed.

I don't really see the difference between the two though.

Well, option 1 implies that there was something else going on before the event described in the sentence. Option 2 is neutral about that.

Compare:

1. I did the work for that last week.

2. I proceeded to do the work for that last week.

Sentence 2 strikes me as questionably grammatical. It needs to be proceeding from something in the context.

Not different enough to make it worth using anything but the simplest one.

I'm of the notion that my certainty is not sufficiently concrete to discover myself in the realm of agreement

Perhaps yet another American cultural artifact. One that - if I were to guess - originated from the Calvinist disdain for ostentiousness.

Yes yes, anybody who prefers plain, easily parsed wording is American.

Wording? Don't you mean diction?

A -> B =/= B -> A.

I didn't claim that this was exclusively American. Though I'd have to admit that one doesn't have to be American to adopt Ameracanisms: rhotic Rs, Netflix color-grading, and copy-cat political movements are other American cultural artifacts showing up across the world due to America's dominance of the zeitgeist.

Rap verses in pop songs wasn't a spontaneously phenomenon across the globe, the origins are tracably American - but that doesn't make all rappers American.