Once 9.0 is LTS and viewless timeseries is the only timeseries format (that is viewful timeseries has been deprecated), we should remove view-ful specific logic from run_aggregate and cluster aggregate. Here are some identified places to remove logic:

• this block (and the associated called functions) that is specific to patching potential bug cases for viewful timeseries in sharded execution and does not apply to viewless timeseries.
• this clause about when its acceptable to use $_resumeAfter on buckets collections