I'm kinda bringing this back from the dead but I want to express my thoughts based on a blend of research and experience.
I think running straight human IGF-1 will in fact have site specfic growth since it doesn't circulate in the blood very long. Location matters greatly here.
As for LR3, I think after a certain dose (upwards of 10mcg/day) it doesn't matter at that point. There are only so many cell receptors for IGF in a trained muscle cell and after a certain point the receptors will be fully saturated with IGF, meaning the rest of the hormone begins to travel to other areas of the body, attaching itself to various receptors as it can.
The same exact statement can be said about MGF and Peg-MGF. MGF-1 has a short half-life, so location and timing is key for stem cell regeneration. Peg-MGF will simply move itself to the areas of trained muscles over the course of a few days.
Also, IGF-1 competes with MGF and since IGF binds more effectively to the receptors, you should not run IGF-1 LR3 w/ pMGF at the same time. They should be alternated week to week or month to month unless you decide to use a short-acting IGF like DES, which then could be used every day alongside MGF or bi-weekly doses of pMGF.