Thanks. I added to that thread. It is a simple module, but if it is part of torch.nn the likelyhood of simppler implementation would be higher.
Relying on forward is good if you own the code, or if there is no standard layers you want to manipulate. But if for example you want to take official  resnet34  and do something to it, suddenly you realize that some part of the model is in forward that could have been in __init__ as a module. Manipulating a dict is simpler that code.