How to make a blurry be clearer

You can run a denoise filter on the Highpass layer, and also increase its contrast. I deliberately pushed the heck out of this to accentuate noise.  Click to expand the screen shots.

Original

Highpass 4.0 set to Hard Light (to accentuate noise) Some sharpening, but the noise is much more noticeable.

Highpass 4.0 set to Hard Light, and Topaz DeNoise same sharpen effect, but without the additional noise.

Same as the last screen shot, but with the clipped curves layer to increase contrast of the Highpass layer.  Still more sharpening, but without the noise.  Some halos apparent, plus CAs between the stag and much lighter background (I made no attempt to reduce CAs in ACR)

So you do have options with Highpass filters.  For instance you can use it in two stages, one with very high value (20) to improve local contrast, and the second at more usual low value (2) for high frequency sharpening of smaller detail.  You can chose between Soft Light, Overlay, Hard Light and Vivid Light for increasingly stronger effect (at the cost of noise), plus you can run denoise and increase contrast of the Highpass layer.  I used Topaz DeNoise, but the noise filter in Camera RAW is very good.  The clipped curves layer adds to the sharpening effect, and where halos become too apparent, you can paint them out of the layer mask.

I deliberately went over the top for the sake of demonstration, but more subtle applications work exactly the same.  In fact I'll add this trick for killing the CAs. Add a Hue/Saturation layer, and use the RGB drop-down and chose the errant colour range.  In this case it was mostly Red. Take the saturation all the way down, and reduce lightness to kill the resulting halo.  Invert the layer mask, and paint over the CA with white.  You can do this with more than one colour band (seeing as CAs tend to come with two colour components).

It's difficult to understand exactly what kind of sharpening you want here, because these images are very noisy. Any sharpening will mostly emphasize the noise, even at a high radius. This is ACR at radius 3 but detail at 0: