Barrel tuning info required

I need info on tuning the malossi 136. With the exception of enlaring the cylinder base transfers , I would appreciate any info on exhaust port alterations etc; as in „the port must be raised no more than 1mm“

the link below doesn’t really provide and specific info that i could decifer.

or maybe you know someone, who can pass their experience of malossi barrel tuning expertise on to me