Mirage question

[Oscar77]

To answer your question directly: No if you focus your scope at 500yds, it will show the mirage at 500yds, not a "compound view" of all the wind.

Not sure if this helps............. I shoot alot of Service Rifle out to 600yds ........
I focus my scope at around 200yds from me....... so roughly 1/4-1/3 of the distance away from me ....... so that the mirage I'm looking at is the one closer (to me) as that wind will have the greatest effect.
(I don't focus my spotting scope on the target at all.......as what ever wind is there...........for all intents and purposes, doesn't matter).
I don't use these words but in trying to explain this ......... here we go............... I use that as my primary wind call and then adjust from there.
So if I realize that there are "conflicting winds" I simply add/subtract in my head to make a call.
Part of that decision making process is what is making me "see" the conflicting winds......... eg Flags, dust, previous shots....... etc. And how much I trust them.
What I don't do, and don't think anyone does (but could easily be wrong), is scan the mirage using my spotting scope --- as in adjust along the route of the bullet, as you seem to suggest.
(Because you'll end up lost, for lack of better terms).

The whole goal to either watching the mirage or some other wind indicator (say flags if it's too dark to see the mirage) is to find a "as-best-you-can" indicator of how the wind might effect the travel of the bullet.
Then once found, use that to then watch for pick ups/drop offs and direction changes.
If you are constantly shifting from one mirage or flag etc you are simply increasing the chances of "getting lost" and using indicators that AREN'T accurate.
Another way of putting it is, in a perfect world, you'll find a "prevailing condition" and then adjust as the wind shifts off that.

It's dated but still VERY good.............. find the book........ "Wind Reading" by Lisa? Cunningham. It's a collection of comments/strategies/tactics by numerous nationally ranked shooters she interviews.
Read it.