The Self-generating feature for LHB coaches was a failed experiment. The FIAT bogies were not really designed for attaching alternators and slef-generating equipment. It's either HOG or increasing platform lengths to accommodate longer trains going ahead.
The HOG for WAP4 has been too long in the making. These are the most numerous passenger locos on IR and CLW is very well versed with it's design as they have been building tap changer locomotives for over 45 years! It's really puzzling as to why it is taking so much time to come up with a HOG system at least for the WAP4's.