Safety pilot time is not flight time
The safety pilot exists solely for the benefit of the pilot under the hood, not for the benefit of time-builders. Simply don't log it at all. You're not flying. You're looking out for the other guy so he can practice instrument flying in VFR conditions. Maybe the guy under the hood will feel grateful enough to sit as safety pilot for you when you want some instrument-reference practice.
It's not flighttime, don't log it. Timebuilders are all the same, trying to wring hours out of every poorly-worded FAR or shakey situation.