I believe a single plant is by far the best option. Also for future expansion, usage of waste heat and low cost, the best site by far is Macaulay Point pump station, as it already has the outfall and is surrounded by acres of vacant land owned by the feds that is not being used.
Clover Point is a totally dumb idea as it is too small, will be dangerous for workers and operators and very expensive to maintain.
Also there will be issues with dewatering during construction and after it is built.
Sewage plants and other industrial facilities with restricted access, especially those with huge switchgear and high voltage equipment, are bad news. The mayors have so screwed this up is unbelievable.
Note, I am a retired mechanical contractor with extensive experience in the CRD sewage plants, as my company completed major work in all of them over the years.