The close-by gun vertex time offset is currently set with respect to (0,0,0), see https://github.com/cms-sw/cmssw/blob/master/IOMC/ParticleGuns/src/CloseByParticleGunProducer.cc#L99, which is fine for a non-smeared vertex, but would have to be adjusted in CMSSW for a smeared vertex.
The close-by gun vertex time offset is currently set with respect to (0,0,0), see https://github.com/cms-sw/cmssw/blob/master/IOMC/ParticleGuns/src/CloseByParticleGunProducer.cc#L99, which is fine for a non-smeared vertex, but would have to be adjusted in CMSSW for a smeared vertex.