I didn't 'BUG:' this, since it took so long to get a working TOC for the Collins Latin dictionary. And I doubt anyone would miss an index.
The IVP dictionaries are odd (and good) since the subject entries can be repetitive across the volumes. But each volume index (subject, verse refs, etc) is for that volume.
IVP's pretty disciplined in their theological perspective, so I was going to create a master index of all my IVP's. I could quickly see their coverage discussion across maybe 10 dictionaries.
Then, I noticed the indices (fodder for my master index) dribbled out in the NT group. Gospels, little. Paul zippo. 'Later', really zippo. Sigh. It would have been a nice PB.