Future perfect

CalifJimBut how many Americans really say it that way? Not many, I'd guess.

Thank you, guys! I can’t tell you how much your comments are helping!

But here’s the part that’s still confusing to me. Some of the Americans I’ve talked to consider the original sentence (with “will have visited”) odd and unidiomatic.

Similarly, this is deemed as standard:

(knock on the door)
— That'll be Richard.

… while this is described as weird:

(knock on the door, the person leaves)

— That will have been Richard.

At the same time, Brits seem to be unanimously okay with such forms.

Here’s another example:

— Where’s Richard?

— He will have gone out. (Meaning he’s most likely gone out.)

Sounds fine to Brits, but not so fine to some Americans…

I’m not really sure what to make of this…