There is a problem with obs_test which is really my fault, but I think you are in a better position to address it.
When I made my modifications for the RFCs, I modified testMapper.paf, not testMapper.yaml, and I was treating testMapper.paf as the reference for my ultimate comparisons of before and after. (I do this by creating a Mapper of each type and looking at its internal datastructures).
Now that testMapper.paf is gone, testMapper.yaml has taken over, and many of the datasets in the two are different (and most of my cleanup and deletions from
DM-8128 are gone.
All of the other Mapper.yaml files appear to create the same exposures and datasets, so they are all functioning as equivalents to the Mapper.paf files (good)
One other issue I am concerned about is that between the two of us, we have pretty much removed all of the original comments from the paf files. Plus, since your Mapper.yaml files are alphabetized, there is really no possibility of keeping the datasets and exposures in sections according to their use in the code. Those two things will make maintenance of the yaml files difficult (for example, if I remove a Task which makes use of 5 different datasets, I will have to hunt around to find them and delete them.