Much quicker and more streamlined now. They will get theirs the exact same way they got the last checks, just faster. If the IRS has their direct deposit info, they will get theirs just like you got yours, now or very soon.
If not by mail in the next few weeks as longs as the IRS has their current address. It's not done by region, but mailing the checks was done by income brackets before and I think that's how they are still doing it.
If they never got any checks and have to file on their taxes, then they will have to do the same with this one as well, that's the worst case scenario.
Yeah I think they are way more streamline now. The first round of checks was so abysmal, that they are going through extra lengths not to repeat such a thing. Plus, they've had plenty of practice by now. Your folks should be seeing their checks very soon, I think.