A good use case for Postgres Schemas?
The development process has falsified the premiss of the question, i.e. each of the 2 derivations of metric1 have become inputs to derivations at several metric levels.

If this had not been the case, I'm now inclined to implement the original scenario via alternate views that duplicate query logic while being based on one or the other derivation of metric1.  This seems from my pov a simpler approach, in that it avoids an additional schema and instead adopts a view-naming convention where view names denote the particular metric1 derivation.