They "simply" mill off about 3/4 of a mm & recut the squish area --Out here in the high country it's mandatory to do this to restore compression. The #1 way to more power is compression and it should still run fine on premium pump gas. Higher compression rearranges your power more towards the bottom to mid range with just a bit of top end loss -it just won't rev as far. Supercross engines run much higher compressions yet [and require race gas] but pull really hard down low.
You can get a good explanation of the squish band...what it does, how its size/angle effect performance..on EG's site.
OK...it used to be there....I didn't go check to see if it still is.
It's not so much the 'dome' (if you're referring to where the plug is) as it is the º at which that 'dome' is 'blended' into the piston crown area. It's at the edge of the combustion chamber. A lot of magic going on there regarding turbulence, flame propagation and 'stuff'.
An input of "squish band" on google gets you about 1000 hits........
If you didn't check the above link, you missed this:
'There are quite a few things that can be tweaked in the combustion chamber to change performance (notice the word "change"..... not necessarily "better" or "worse".... everything is inevitably a compromise). '
I don't know what you're expecting as a result. If, after you talk to ron about it, it sounds good to you......do it. Ron won't steer you wrong.