Good grief.
There are a lot of things on the Magnepan website that I do not fully agree with, ranging from outdated experiences to technical explanations more marketing than engineering. But it's a really cool company, you get to talk to key players if you give them a call, and I like their sound.
Twenty years ago, and even ten, class D amplifiers had a lot more issues with low-impedance and reactive loads than they do these days and a number of them measured and sounded worse than their AB competition. That is hardly true today; essentially only the cheapies that are poorly designed have issues. And Maggies are a low but relatively benign load. The problem I see more often is AVRs that cannot sustain the power needed to play them very loudly in a large'ish room.
The ribbon tweeter in particular dips low in impedance but all the plots of Maggie impedance for all models over many years has been similar. Some dips around the crossover(s) with relatively broad and mild phase variation. As for experience, I first heard them in 1978, got my first pair in 1979, upgraded in 1988, listened to many along the way and since then. I worked for a couple of Magnepan dealers, helped install them, test them, mod them, repair them, etc. I have heard them with dozens of different amplifiers, tubes, SS, class A, AB, G, H, and a few class D, and did not notice any significant difference in sound with any of the newer crop of class D amplifiers compared to other SS amps. Bass sounds better to me and highs essentially unchanged.
ESLs are a much bigger issue as the impedance dips at HF and has a high phase angle. But a lot of conventional designs are as bad or worse, particularly in terms of the range of impedance magnitude which is often enough 4:1 to 10:1 or more.
As for blowing fuses, many have done it (and with many a speaker), but there is normally far less power in the midrange and treble region, so unless you are very exuberant fuses should not blow. You need all that power for the bass region which can easily demand 10x to 100x the power of the midrange to sound the same. If you are worried about sending all the amplifier's power to the tweeter then do not buy more than say a 12 W amplifier but don't complain to me about the lack of bass and volume.
FWIWFM - Don