Gachinski had videos of 4Flip & 4Loop.
Yes, Gachinski was reported to be landing all of the quads except Axel a few years back. They were planning to add the 4Lo as his third quad in the 2011-2012 season but decided to focus on the second mark more (that was the year he almost won Euros).
On the American front: Jason Brown has been landing a 4T in practice since last May but it hasn't been consistent enough to put in competition. I'll dig up the video when I have time. I've always thought Jason should try the 4F because his 3F is a thing of beauty.
Joshua Farris gave an interview late last year where he mentioned that he'd tried all of the quads in practice except Axel and found the flip to be the "easiest". His 4T is inconsistent in competition but it's always rotated and it's a beauty when he lands it.
I haven't heard that Max Aaron is planning a different quad, just trying the same two he already has. That might be a better idea.
Oh, and there was a video of Plushy's 3A-4T getting around at one point. I can't seem to find it at the moment. All I can say is that I can see why he thought it wasn't worth it - it looked back-breakingly difficult.