I haven’t tried this (yet), but perhaps it can help with the Dev-vs-Prod .yaml files:
Once it’s understood which elements of the .yaml file are (should be) common to both, and which are not – some of which will vary from project to project – then it should be possible to automate the transfer of the common parts from one to the other.
In the meantime, that diff listing may help. Ordinary line-oriented comparisons are doomed to fail, because much of the data is unordered, and may be saved in a different order/layout each time.