I saved MANY GG#4 seeds from buds I bought on the commercial market. I assumed they were from late-flower 'nanners. At the time, I loved that strain and I was willing to take a chance on growing one or two of them along with my other stuff. The plant that I ended up with, produced some very stinky flowers...very oily and resinous as you would expect from GG#4....BUT, the growth characteristics of this particular phenotype showed long red stems with golfball size buds and almost no fan leaves -looked like I had lollipopped it, but I didn't!
I've grown bag seeds several times and it's been hit or miss. But, it's also hit or miss with many well-known seed banks, too. This last grow, I bought a pack of Chemdozer seeds from Archive and paid out the nose for them....BOTH plants showed some balls in early flower -which I picked off. As far as I can see, it never showed any more after that. I suspect that the Chem91 mother was the culprit -as the Chemdog story has its lineage in bag seed genetics, too.
I don't think it's uncommon for even the best genetics to throw some 'nanners. There are SO many complex hybrid plants now, most all the strains end up having some lineage to plants that have this trait to a greater or lesser degree.