>Thanks for that, in this case what is the proper way of >dealing with these is a touch on brightness/contrast >reasonable when highlights have been dealt with at start of my >workflow?
The best place to deal with these is in your sharpening edit steps. Creating new steps to cover up the faults of others often runs you in circles
To add to what pwarbeck already said, I would suggest that you create 2 identical USM Mask edit steps in CNX. On the 1st edit step use the Lighten blending mode, on the other use the Darken mode. If you're applying this sharpening step locally, you should link both instances in the same edit step so they both can use the same selection.
This gives you control over both the light sharpening contours (halos) that are causing your highlight increase. and the dark contours as well. I suspect that you're not blowing out highlights as much as seeing a general (objectionable) increase in luminance caused by the light contours in your sharpening steps.
I believe if you uncheck the step using the Lighten mode that your objectionable highlight increase will vanish, but as a result your apparent sharpening will be somewhat diminished as well (but not completely because the dark contours are still there). The answer to this rock & hard place situation usually lies somewhere in the middle in the form of a compromise. Generally speaking a simple opacity adjustment is all you need to find a happy balance between the two. And though it's the nature of the light contour in sharpening to introduce some degree of unavoidable "highlight increase", by adjusting its opacity down you should be able to find a point at which the highlight increase is no longer objectionable. Since you have two sharpening steps, you now also have the option to adjust the sharpening Amount, Radius and Threshold independently for each contour if need be. The trick is to adjust the light & dark contours so that neither introduces objectionable artifacts but still sharpens the image. This is of course a subjective process as what is objectionable lies in the eye of the beholder.
However, this isn't as straightforward with High Pass sharpening as it already uses a blending mode (Overlay), but I suppose you could get creative and find a way if you really had to.