In my opinion....the engine head is a precision part, it cannot be repaired/adjusted without precision tools and factory service data...which is obviously lacking in our repair set ups and mechanics...that's why the sound and performance of cars goes down after any engine repair activity done by such mechanics and issue is masked by saying that ' isko chalao, jab rawan hogi to theek ho jaye gi' but sadly this never comes...
so for me...replacing such parts is better than repairing them...
if the engine head is resurfaced two times...and shaved twice....then the cylinder capacity is reduced increasing the compression ratio meant for such engine....some mechanics install thicker head gaskets to address this issue but again its a precision job and cannot be done by andaaaza..
hence all dynamics of engine are changed...ECU is programmed according to certain CR, so it goes in circles with altered engine....never achieving performance and efficiency..
better to replace the head with a factory spec one in good condition...and also remove all JUGAADS to mask the issues faced in tunning after the head shave job....
my two cents...