I have a goat and stash too.
I have shaved the goat many times but I hate the feeling of the stash being gone. ITS HERE TO STAY!!

Many use a two handed aproach for the chin to lower lip. Holding the razor steady and moving the face to get that spot.
You can do it one handed like anywhere else though, just practice.
The stash coming from under nose down - first pass, coming at it from the sides for XTG then two handed for the upper lip to nose - similar to the chin area for Against the grain.
Two hands for under the nose against the grain is helpful in retaining the nose apparently