It probably (note probably) has more potential for use off site RE SEO than on site for SEO the more I think on ways things on the subject.
I have tbh only had one dealing with a domain redirecting to another as I personally think it is a bit stupid as well as lazy and pretty un inspiring or inventive but here is the case I dealt with
I did some SEO for a guy who is an artist of a particular discipline and during the process it got mentioned that exact match domains and domains with keywords in and how well they worked unless a person was lucky enough to have a brand name.
Anyway to cut a long story short I got the artists some page 1 results in exchange for some artwork I needed doing. Bit of old style bartering just with both of us doing each other favours exchanging skill sets.
A year or so later (yes this is the short version) I noticed the artist had let his domain name drop and was indeed using a domain related to his profession.
Problem here was though he had all his back links in place for that name and a page in place with "Pending renewal or deletion". Which I watched during the week I thought it would drop and I caught it.
The artist had installed his old site on his new artist related domain with no thought of his many portfolio links built up over 8 to 10 years.
I put up a page with his contact details on and waited (we had sort of fallen out as he was a moody artists type with no time for annoying SEO types likes me with big ideas).
Eventually he contacted me moaning people we're finding him via his old domain name and why had I got it.
I explained and sort of sold it back to him for the cost price plus a picture (though he still owes me a piece of digital art as it happens come to think of it).
Low and behold after all I told him about putting another (what amounts to a five or six page) site in place he goes and redirects his old domain with 10 year history to his new domain with a now 3 year history.
Yes his new domain does well for the exact match searches I told him it would but he could have so much more without that redirect.
So although I have said there are ways both on and off site RE SEO to play some games with words and the SE's it is really better to have seperate sites.
It takes next to no time to put a fairly useful 5/6 to 8 page website online and to get a bit of advice or an idea on what is needed to SEO such a site.
It is not quite a matter of whether SE's are smarter as using keyword domain as redirects has nothing to do with black hat or anything shady where them being smarter or not is the factor to consider.
The main thing about redirects unless there are very good reasons (which I can already think of) is that redirects are in most cases are a waste of potential internet property over all and in the main even if they do have uses being used in such a way.