[niterydr]

They do sound like regrinds.
Nothing is wrong with regrinds as long as you maintain the same clearance between the cam follower and the cam. (I hoped you guys checked that SLS).
The valvetrain geometry changes, but is very negligible, especially on a HLA system.
As far as shimming your HLA's. People have been doing this for years. Its not bad if done correctly, and since they are in the head, below the HLA, I wouldn't worry about it.
The important part is to maintain proper clearances between the cam follower (rocker) and the cam. To tight, and you could collapse the HLA, to loose, and you could send it on a trip somewhere else in the head or through the valve cover.
Have fun!