Maybe just vfast partitions are cut-off? It seems, that people using native linux partition on SD and/or any ext, doesn't get it unmounted during cover removal.

as for glueing magnet, I'm using this for ages and haven't noticed any regressions. I'm just able to take cover out at any time, which suit me, as I've glued a cut-off part of microSD box (this one with small holder for SD) and I hold backup microSD inside cover.

/Estel