My read was his issue seemed to be batch specific from scanning the thread.
Since gyno is closely associated with higher levels of GH, when using xx mg of two brands/batches, and one is inducing gyno but the other isn't, that's pretty strong evidence one is effectively delivering more GH.
Overdosing is never more than ~20% so that's unlikely the cause of dramatic gyno.
Immunogenicity against GH develops in a pretty high proportion of users, it's just not well documented because clinically it rarely rises to "significant" level. Significant being defined as very slow of no growth in children, or a similar lack of response in IGF when treating adults. Some lesser amount of effectiveness loss is likely quite common. (see inhibition in the chart above)
So while gyno might be caused by some unique mechanism(some odd impurity for instance), I think this is one of those "if you hear galloping think 'horse' not 'unicorn' " situations.
For those using GH long term, a GH antibody test every 6 months or so is probably a good idea. The added complexity for UGL vs pharma however is batch to batch variance. So unfortunately a UGL brand that works well, with low immunogenicity, may completely change on the next batch if the UGL changes something, while pharma is going to be extremely consistent.
If I was using a UGL GH and had no antibodies develop while on it, I'd buy a long term supply and store it in a cryofreezer.