Measured mine, it's exactly 1/4" from the top. This is a hand applied decal that is applied by multiple individuals at the factory. The OP says originally it was 3/16" and is now 5/16". Then add in template variations. The new decal is only 1/16" different than mine. I do not see an issue.
Look at the Michelin site, it says the same thing 10.5.
305/30ZR19 (102Y) XL BSW
Section Width on Measuring Rim Width
12.30" on 11.00"
Max Load, Single (LB @ PSI)
1874 @ 50
Rim Width Range (Min/Max)...
Looking at Tire Rack, Michelin has 10.5 as the minimum range for the 305