looking for advice to mitigate inner groove distortion

Well now lewm don't be so hasty. He also said it could be the suspension. He already gave it an alignment. Maybe just needs new shocks?

Yeah lewm I also can't think of any alignment issue that puts a halo around horns. While I would like to nail down the overhang situation the halo and crescendo comment sounds more like mis-tracking to me. 

Adam, maybe double-check VTF and if not max maybe try a little more.

It sounds like you’re using one of the freebie alignment printouts?
Some of those are okay for alignment only after having set overhang.
How did you set overhang?

Overhang must be set accurately first. Otherwise if overhang is off it will cause your cartridge to be rotated too much one way or the other, which you may not notice until the inner grooves where it becomes more obvious.

My favorite for being fast, easy and accurate, is the MoFi Geo-Disc  https://www.mofi.com/product-p/mfslgd.htm which you will notice has a ridge line running A to B which must be aimed directly at the tone arm spindle vertical axis. Then you tape the platter so it doesn’t move while you’re tweaking alignment.

Even though you are not using the Geo-Disc nothing changes. The Stevenson you’re using must still be placed accurately in relation to the tone arm spindle, and both the gauge and the platter must be held stationary.

Try again with these tips and overhang set first and see how it goes.