Patches copied to composer.json causes 'patches-file' to be ignored

Problem/Motivation

We use the patches-file feature of cweagans/composer-patches to store all patches in a separate file. If patches are copied into the root composer.json by drush update:lightning --upgrade (i.e. when Lightning Layout is installed), this causes patches-file entry to be ignored by Composer, and any patched code (modules and/or core) will be reinstalled sans patches on subsequent updates.

Easy enough to copy the patches to the patch file, or remove them entirely, but something to be aware of.

Not sure if it's worth adding to the release notes where the Panels/Panelizer patches are already mentioned.