[Galaxy Note 10.1 (2014 Edition) Accessories] Sunfire-:
Just heard back from Incipio: their Lexington also has a Smart-wake/sleep feature, so it has magnets (which is unfortunate to some). However, I'm glad they took the time to respond quickly, so there's that. I'd probably be investing in the Feather case and just using some sort of sleeve.

When I got the MoKo ultra slim case, I had no problems whatsoever on days one and two. I did a line test at the top (near the camera) and the bottom (near the physical and capacitive buttons) pretty much every day since I got the case (whenever I turned on the display to use it), just to be sure the magnets weren't doing anything. The line test was simply trying to draw as straight of a line at those edges near the magnets, with the case open as flat as a textbook, or folded 180 degrees on itself like holding a magazine one handed.

I didn't notice any symptoms until about day five or so later after getting the case. I think on day four, I definitely didn't have an issue with the line drawing, but when I went to draw on day five, I did a to-the-edge type of art and I noticed that the lines started to 'dodge' the edges closest to the magnets. When I did the line test afterwards, I would try to draw a straight line and the line would bend away from where the magnets were. When airbrushing over the same location, the paint would also dodge so that there'd be a small circle of uncolored area. If you pressed down hard-ish, you could draw in the area with some degree of inaccuracy, but lighter strokes would definitely dodge.

I think I left the case on for an extra two to three days, just because I didn't want to have the Note bare and unprotected, but the problem persisted enough that I just had to contact Amazon/MoKo for a return. Removing the case made the symptoms disappear entirely and instantly. There wasn't any lasting effects; however, I left the case on for only a week, so not sure if I can qualify a comment on permanent damage. I can only attest to the annoyance when the case was physically on. The digitizer should immediately be fine after you remove the case, should you encounter the issue. I don't know if anyone (with the problem) had kept their case on longer than a week.

Anyway, I'd imagine that some cases have the magnets installed in various places on the cover and varying magnetic strength, so just try to figure out where the magnets are on the case, then test specifically around that area every now and then. Hopefully you are one of the lucky ones that never see this issue (or at least that you got one of the cases that have the magnets in places that don't affect obvious areas). I don't know why the problem got noticeable after week rather than day one, but that's pretty much the only reason I had to reluctantly return the MoKo ultra slim case (it is made really well and feels very premium-like).

I'd also note that if you're not using the device for artwork, illustration or design work, you may never actually encounter this issue in regular use (i.e., note-taking, apps, editing photos), so it may be possible that some users that report no issues don't use their Note in the same manner. Hard to say really, most people just say they either have problems or they don't, but they also don't really mention specifics like brand/model of their case, what tests they performed, or when they performed them.