at your own risk...

just my 2c, but when i pencil mod, i take the initial reading, pencil, take a reading and when i am happy, vacuum the graphite dust, take another reading, and if it is all good, slap a small piece of tape over the area.

I lowered the resistance by 10 ohms from 330+/- to 319, and when 1.725v is set in bios, i get 1.82v actual w/ dmm. Now stable at 450.