I'll get back to the optics discussion later as its a pain to type on my phone....
But as for the weight...I'm all for lighter weight stuff where possible...but if the weight if your rifle scope/ rifle is going to make or break your hunting trip, chances are you are too weak to be out hunting in the first place.
Let's walk through it slowly:
How much magnification do you need to hunt elk?
Realistically, 7 power is plenty, 9 power max. Any more than that, you're too far away to begin with. Perhaps not on the internet, but certainly in the real world. Remember we're talking about elk, not ground hogs.
Besides, the low end of a 9 power scope is 3x, which is about the maximum you'd want for close shots in timber, a far more realistic possibility than a 500 yard shot.
So 9 power. Given a
generous 6mm eye dilation / exit pupil (and if you don't understand eye dilation and its relationship to exit pupil and why it's important there's no point it posting), the maximum
useful objective size is 9x6 = 42. Anything over 42 is WASTED because while it may pass more light, your eye can't let it in, and 40 is close enough to make no practical difference.
So a 3x9 40mm is all you need for elk hunting in the real world. QED.