But I'm not quite sure there is a sure-fire becoming of a giant. I don't know and would need to experiment to be sure, but it may only be mamlauks, it may be only with the lug edge, or other things.

One thing for certain is that they "grow". Early on in life, there are certain entrances and exits to the clan village that you cannot take later on in life because you can't fit through, so there is a "growing" thing there. Whether or not you officially giant size, I don't know. I would like to think that you can still bash reduced gnomes.