Best write-up ever made on the topic
There was a user struggling with battery life on 6th-gen Thinkpad X1 Carbon on FreeBSD Forums a while ago; he reported on Youtube that my tips had proven useful in prolonging it by 30-50%. Much of this is already in your blog post, sharing it it anyway for reference
I omitted drm-next-kmod/drm-stable-kmod but I will cover them in the update to this post.
I thought that drm-next-kmod will be merged into 12.0-RELEASE but now not sure.