Regarding the Reddy's Hole option... I've seen that route marked as well, but haven't had a chance to explore it. That said, there are no junctions at either end that indicate the start/end of the trail, so I'm guessing it is in even worse condition than the "low route" I took. In 2018 I climbed up Fleming Mountain, visited Rae Lake, and walked up to Mosquito Pass and I didn't find any obvious spurs. But I did camp in Long Meadow with a hiker who has explored this area for decades and he talked about how wonderful the area around Reddy's Hole and Red Rock Basin is - and indicated that "old" trails went through the area. If the terrain is snow covered, I'd stay high, because it is shorter and nicer snow-walking out of trees, but if dropping down got me to dry trail, I'd probably take that this year.
