Hmm, it's an interesting route. I considered some things like this before I settled on the one I currently use.

I'm fairly certain the Memory Crypts -> Leg -> CC route is a good bit slower than SH -> HI -> CC, but it does have the advantage of bypassing the level 4 Karma requirement to enter the Wall from CC, which is about half the reason I don't get the Wall echo in my route (the other half is that it's a pretty long detour).

Having to go through the top of LF... I'm not sure how good that is. The fact you don't need the LF echo helps a lot, but the topside of LF just sucks. Shamescissors found a method that can let you get through LF_H01 (the really long deer room) without needing a deer at all by using some grenade-boosted wallpounces, but I'd say it's too inconsistent to use in a real run.

Needing to go through LF_H01 is the main dealbreaker for this route, I think. Deer are very slow and inconsistent, and I find you will very often be killed by invisible scavs if you try to deerskip through that room. The extra distance needed for the Leg route and detouring up the Wall doesn't really help either. There's definitely some good improvement potential here, though.

Starting as Survivor, get enough food to hibernate, and then make it into the first shelter after the starting room and hibernate at precisely 1:22 on the in-game timer. Milliseconds don't matter. If performed properly, this guarantees a pup will spawn in SU_S04 (usually the second shelter you'll find in Outskirts).