Hmm haven’t tried one like this. Looks like the arm is bendable, so may be able to get a similar angle. Questionable suction grip aside, this probably works great for the “tiny music stand” use case…but I think the main issue here for filming is that you’ll likely get a ton of vibration / shaky footage.
For our recent Andy Wood mandolin stuff (example here) we used the GoPro Jam, mounted on the headstock with the longer segment of the arm removed. Pretty sure this gives a more solid mount than the adjustable gooseneck type would, but even in this case we had quite a bit of camera shake we had to reduce in post.
So almost certainly will give you lower video quality than you’d get with the Magnet, but…possibly good enough for occasional use? Not sure. Maybe worth a try for only ~$11 though!