Yeah, you can lean the plate
to you 10° so the tolerance is -10°, plus zero°.....IOW, 80-90°....can't lean it back past 90°
EDIT:
.....although, I see that you can rotate the face 0-360°....I haven't tested anyone rotating the face around 180° so that the plate is leaned back 10°, so I'm not sure if I'm reading that right.....but it appears that you might be able to lean it back, if you use the option to rotate 180°.
Hopefully more people will chime in..........