The camera blur setting is, indeed, a band-aid fix, but it is only used by the functions called when opening chests, boons, or popup hints, so no other game mechanics are impacted.
I've never been able to reproduce this issue myself, not on any of my devices, which makes me think this is a device- or platform-specific problem. Until I'm able to do that, the best I can do is introduce a setting that gives affected players a workaround.
> just removing the camera or screen blur from locked chests seems simple enough without removing it entirely.
That's exactly what the setting does :)