I would have thought using two anchors anywhere but slow running water would be unsafe.
I intend to use two when floundering etc.
I imagine you could drop the rear anchor, motor over the top of your " spot " and keep going a bit further, paying out line as you go. Then drop the forward anchor, Drift back to your "spot" and pay out line until you get there. Then pull in the slack on the rear one.
Or have I got it all wrong.
Jim