Magnepan LRS speakers require a high current amplifier. Those speakers are power hungry. I doubt the Bluesound Powernode has the grunt to drive those Maggies properly.
The other thing is that Maggies require some setup trials. Many Maggie owners raise them up higher on Mye stands to realize their full potential. They are very direction so positioning is critical. Good luck.
There are quite a number of myths surrounding Magnepans. "Lots of Current" and "Lots of Power" are the two biggies. Lots of Power/Current compared to what, non-planar speakers? 8 Ohm speakers?
Almost the entire Magnepan speaker catalog is rated at 4 Ohm impedance. There are plenty of non-planar speakers also rated at 4 Ohms. For the sake of argument let's compare the current requirements of Magnepans rated at 4 Ohms, and a speaker rated at 8 Ohms.
So, yes, Magnepans do require more current relative to a typical 8 Ohm speaker. They require 41% more for a given power level, across the board. Does 41% warrant the requirement for an amplifier with "lots of current"? That answer depends on your listening levels.
"Magnepans are power hungry." Let's dig into that a little bit, too. It's true that Magnepans are not the most efficient speakers from an SPL/W standpoint, but they aren't too far away from many other speakers in this regard either. Magnepans (and this is true for almost all Magnepans!) are rated at 86dB @ 2.83V input. Given that Magnepans have a 4 Ohm (roughly) impedance, this mathematically works out to be 83dB / W if comparing Magnepans to a speaker rated at 8 Ohms.
It's pretty easy to see that very high sound pressure levels are attainable without mega-power amplifiers. Will someone be happy running Magnepans with a 10W amplifier, especially one not capable of comfortably driving 4 Ohm loads? Probably not, however these days there are a plethora of amps available that are more than capable of cleanly driving Magnepans to levels beyond comfortable listening levels.