I wonder why the SHT plate wasn't designed as 2800' MSA straight down to the base turn at 1800'
Isn't that exactly how it is designed?
I understand the point you are trying to make, but even with YLTV, if you're anywhere near a direct entry, you're going to be (or would easily maneuver to be) in the 3000' MSA sector, and you've got more like 3 minutes to lose the 1300' (2 minutes outbound plus descending in the turn inbound). If you need to do a parallel or teardrop you've got an additional 3 minutes to lose the 900 feet.