Sorry for my slow response
The tuning is not special i think, i just followed what the experts taught us here
I'm on latest cssu testing, with kernel power 53 installed, so ican overclock it whenever i draw. I could draw withouth oc of course, but additional speed is always preferable? Ive been using max oc freq (1150 MHz?).
When drawing, i usually leave no other apps open, especially when the drawing's getting bigger. (If you use MyPaint i think you know what I mean). The phone would be struggling when the drawings grew to reach over 20 mb in size (in my case with over 10 active layers), its the RAM right?
Thats it, i use regular ballpoint pen (emptied ink) for stylus replacement so that i could draw more comfortably.
I hope this helps.

Oh yes, i changed the address (updated in in my signature). Just click it