WDP-4D/ED were rare earlier in BAY - HPT section. But as per my spotting is concerned 51412/51411 got WDP-4D/ED 3 times and 56909-slip/56910 got WDP-4D/ED 1 time (i.e , today) within one week. Slowly WDP-4D/ED might be common like WDM-3D/ED in BAY - HPT section