Unefficient call for parameter in each flux evaluation
I think the call
static const bool enableGravity = getParamFromGroup<bool>(problem.paramGroup(), "Problem.EnableGravity");
in e.g. flux/cctpfa/darcyslaw.hh:162
executed during each flux evaluation is a performance drawback.
May one wants to cache the parameter somewhere, but this is not straightforward since the function is static.