I'm pretty sure that no part of Kiln Lane or the B4440 are highway=trunk. None of them is an A road with green primary route signage, which is what this tag means in the UK.

Please read and ensure that you have understood the documentation before changing any other highway tags.
https://wiki.openstreetmap.org/wiki/Roads_in_the_United_Kingdom

Reverted in https://www.openstreetmap.org/changeset/166946284