Cylinder head milling

mnomis484 wrote:

As a street bike i have got a Husqvarna SMR 510 (2008). When i disassembled the motor to change the piston, i unfortunately scratched the sealing...

As a street bike i have got a Husqvarna SMR 510 (2008).
When i disassembled the motor to change the piston, i unfortunately scratched the sealing surface of the cylinder head.

So i wanted to take it to a shop to have them mill
/ resurface the head while taking away as little as possible, so that the compression does not increase too much and the valves dont hit the piston.

My question is, how much do you think i can take away max.? Would 0,5mm be too much?

And is there a rule of thumb on how much increasement in compression that would be?

Thanks in advance!