Finally I finished my new add-on for tracking (and also highlighting) all the changed bones during animation process. Would like to know your opinion!
How it works: Changed bones are highlighted with pink color (one may select any other color). After all tweaking has been done one can insert keys for all changed bones with one click. Only changed transforms will be keyed.
If this add-on seems interesting to you, please check it in Blender Market for more information: https://blendermarket.com/products/changed-bones
It would be nice to hear your feedback, guys! Thanks!