'Future Perfect' ever really used by native speakers?!

[CarloSsS]

I think the difference might be dictated by the rest of the sentence.

I will finish the job before you get home.
I will have finished the job by the time you get home.

I will travel to Australia before I'm thirty.
I'll have been to Australia by the time I'm thirty.

So something like this would sound unnatural?

I'll have finished the job before you get home.
I'll have been to Australian before I'm thirty.

[5jj]

So something like this would sound unnatural?

I'll have finished the job before you get home.
I'll have been to Australian before I'm thirty.

They are not really unnatural.

[CarloSsS]

Is there any difference in meaning between these two?

I'll have finished the job before you get home.
I'll have finished the job by the time you get home.

[SlickVic9000]

(Not a Teacher)

The past perfect tense clarifies and emphasizes the order of past events (namely, this past event occurred before this other past event). Future perfect does the same thing, emphasizing that one future action will take place before another future action.