Goood article but nothing new here, these ideas have been around for decades and in practical terms nobidy is getting any nearer turning them into reality. The problem is the impossibility of manipulating (either compresing or stretching) time and space because these are not substantial things, but concepts.
Let's try an experiment, not a thought experiment of the kind theoretical physicists are so fond (because theoretical physicists lost contact with reality ages ago, but a practical experiment.
Take a ten gallon bucket, empty out any sand, water etc. that might be in it so for purposes of the experiment it is filled with space, (OK it's actually filled with air but that behaves much like empty space and has the advantage of being breatheable).
Place that bucked on the ground and compress that space, push it down with your hands, stomp on it, hit it with a hammer, tamp it with a shovel, go on work upo a good sweat, we can all use extra CV exercise, and then check how much space is still in that bucket. There is just as much as when you started.
Time is even more difficult, being completely an artifice, a human contruct. Oh I've heard all the arguments about scientific time being different from the time that tells us when we should be eating dinner. The latter is useful, but neither exists in nature. Scientific time however, the arrogant and rather silly assumption that since Big Bang, an event which may or may not have happened, the entire universe has measured its existence according to the revolving of our insignificant planet on its axis as it orbits a rather small star in one of many millions of galaxies.
Just trying to put things into perspective.