This is an old thread so not sure if anyone will respond. My daughter -6 weeks old - also has a "reticulate" port wine stain which is indeed the pattern of the PWS. I am wondering how your son is doing now since it has been a few years! Did you go for the laser in the end? Do reticulate PWS respond better to laser treatment than regular PWS? My daughter has it on her entire leg - so it will be tough to treat no matter what.
All the best,