Vectorize evaluators
JetVariationsCalculator::produce
takes as input the full list of jets, and then does various for loops over all jets: https://gitlab.cern.ch/cp3-cms/CMSJMECalculators/-/blob/main/src/JMESystematicsCalculators.cc#L224
Having an interface for correcting a single jet, that can be mapped on the jet collection, could be more efficient.