That's a good point. I didn't think about the CDS being a little different at different elevations. Can anyone share their experience with those?As others have mentioned, check your zero.
If you have the opportunity, take a few longer shots when you're at elevation.
Close in, your zero might not be that different. At longer ranges is where the difference will be.
Also, don't use a CDS dial.
It will match up at your 1,000ft elevation, but not at 7,000.
If you need to get a MOA or MIL reticle.
They are always MOA or MIL.