I routinely use anchors down to size 16 caddis larva and mayflies.
As you progress further, you will find that absolute contact is not necessary; I rarely feel the flies anymore. Your goal is to make the flies ride the invisible cushion along the stream bottom and tick the bottom once in a while. About 90% of my contact is visual now, only 10% tactile.
This is also due to the choice of sighter. When you use the coiled mono, the coils react with extreme sensitivity. The coils should never be stretched tight during a presentation, only when you have a fish on!
Remember too that there is more than one way to make your flies get to the bottom:
(1) The easy way is to use heavy flies
(2) A better way is too cast further upstream with lighter flies (just like indicator nymphing)
(3) A method that helps to get the flies down is using turbulent water. The water coming over a rock is a good example; the flow on the rock is laminar, but the hydraulic downstream of the rock will pull your rig under. Manipulate your drift to keep it there.
Another comment is that as you progress, you will find that you use the ultra-heavy anchors infrequently. You should only use them for fast, deep water and on windy days. In the high spring water, you will need them more often.
I hope this makes sense. Perhaps one day I will do a Euro-nymphing master class on the stream and I can demonstrate what I am talking about. With a single long-line leader, you should be able to cover all the water types on the Farmington (at this flow) and catch fish everywhere, just by adjusting your rod angle, anchor weight and length of leader below the sighter. You only need 5X.
HINT: Most people use flies that are too heavy and leaders that are too short!