But the number was low and new names could be easily added.
Agreed. Adding new ops is not a problem. Alphabetizing the oplist and renumbering the ops was unnecessary.
There was never a public discussion about this policy change.
I remember several public discussions, at least in multiple #ps meetings.
If PBC now is not sufficient after the third rewrite what is still missing?
The last time I looked at PBC, it was still too tightly coupled to the internal layouts of various PMCs, especially the Sub PMC.