Was able to get +212 on the core and +266 on the memory at stock CPU speeds. 9300 score on Unigen Superposition at 1080p extreme test.  Haven't adjusted any voltages through afterburner yet.  Does EVGA let you do this?

yeah, I could only get +111 and +600 on mine (GPU Clock and Memory clock respectively)..
 
 

 
 

Supbruhtv
Was able to get +212 on the core and +266 on the memory at stock CPU speeds. 9300 score on Unigen Superposition at 1080p extreme test.  Haven't adjusted any voltages through afterburner yet.  Does EVGA let you do this?

 
Yes EVGA allows you to OC your card

What GPU ?

Stock MHz with sliders full right for Temp & Power Targets ? (this would be your baseline)
 
Room Temp?
 
Now with your settings ---> What is the New MHz displayed ?
 
What benchmark are you running to load your GPU ?

Yeah sorry I kind of forgot to include the card.  It's a 2080Ti XC Black Edition.  I don't really have a thermometer is my basement but the max temp of the card during testing was 66C.  I realize EVGA allows you to overclock your card but my specific question was about the voltage slider in afterburner.  It's greyed out by default but you can enable it in the settings so I left it stock when OCing.
 
For the test I slid power and temp targets all the way to max.  The benchmark I ran was Unigen Superposition 1080p extreme.  Made it to like the 5th page of the leaderboard with a 9300 score.

Basically I was asking how I did in terms of what other people have experienced (i.e. how my card's overclock seem to compare to what others have experienced).  I do have an XPSC waterblock ready to go (I forgot to order a backplate lmfao) so I assume it'll push a bit further when I reconfigure my loop with it.

the_Scarlet_one
Afterburner requires you to hop in the settings and change voltage to “third party” so you can use it.

Give that a shot. It is on the main settings screen about 3/4 way down.

How far on the slider (0-100) is safe (and warrantied by EVGA) to go?

Nvidia Boost 4.0 is in the drivers seat.  Unlike 900 series cards and before, when you could force the voltage.
 
You are trying to get the most out of your card - setting the stage to allow it to perform 

Boost 4.0 has the last word - looks at total Load, Watts & Temps - then it decides what to allow - or what to reduce
 
Boost 4.0 will pull your clocks down in 13 MHz steps to control the heat.