OK, but the fact appears to be that even before any of the mentioned advances, quartz crystals are NOT the bottleneck. I repeat, the clock already isn't the first bottleneck. The MEMS sensors have been the bottleneck all along.
So if you get the impression from the article that quartz crystals used to be the bottleneck, but due to their breakthrough, MEMS sensors are the new bottleneck, then you've been duped by the dishonesty of the article. It is this dishonesty, along with the implication in the original article that their advance makes satellite-less INS feasible, that I'm questioning in this thread.
I mean, looking back at the article, I see they're using words like "one step closer" in various places. So maybe my objection wouldn't hold up in a strictly technical court of law. But that doesn't make it any less slimy or clickbaity. Also, "without the need for satellite signal" is a bloody great stretch given that even the best INS's need occasional feedback, which is almost always from GPS satellites or star trackers.