It doesn't move much on an animal that's standing still.
Personally I prefer a frontal shot out to about 400yds. If there straight on my aimpoint is the tip of the sternum, slightly quartering I'll use the crease of the neck/shoulder junction looking to spine them.
A little low and you wreck at least one lung and run the bullet the length of the vitals. Nothing runs far with all their pluming wrecked.
If animals stood still all the time, would we still call it hunting? Come on, you should be the one telling me stories of 'things that happen during time of flight'!
I realize the YouTube example you provided wasn't your own. Anatomically, it's actually one of the more accurate representations I've seen, which is notable. Still, the elbow is not a safe target (Unless, say you're zero'd at 300 and the elk is at 150)
The OP mentioned a couple of examples of elk appearing bullet proof when hit low, good PSA! Those who do well aiming for leg bones are shooting big bores at close ranges, and they are certainly not using VLD's.
It's always interesting discussing shot placement with someone as experienced yourself. Rarely are two presentations ever the same. Angle, aspect, distance, wind... the illusive 'bang-flop'... I too have found frontal shots seem to provide 'instant results' more often than 'side address'. There seems to be a 'shut down' switch above the heart and below the spine - I don't always find it, but it's real satisfying when I do!
Bull Elk are hairy beasts. Their skeleton is not well defined, even to someone who has deconstructed a few.
As much as we enjoy debating the finer points of placement, in the spirit of general education, I'm sure we can agree the fundamentals are pretty simple. Keep impact in within (vertically) the middle third of the torso, slightly fore or aft of the shoulder (depending on presentation), and let the work begin!