I recently was trying out "Daisy01 Large" from the lawn presets.
Using the preset at default settings increased my render time by more than 1 hour.
It seemed it was spending an hour long pre-pass which prompted me to investigate the v-ray materials for that forest.
Well, I found in the vast multi-sub material were some materials that were VRayFastSSS2.
I switched it to a normal VRay material and it made no visible difference in my render (at least not to warrant a >1 hour pre-pass!)
Also after changing from VRayFastSSS2, it rendered with no pre-pass and quickly.
So, I am requesting that that material type not be used in the preset/defaults. If someone needs to use that for some reason, let them go in and make the change. I can't image the majority of users will want to pay with such render time increases.
So far, I have only encountered this on this particular preset.
Thanks in advance.