We just had a job go through that it was claimed at some point was going to be black only plate changes, but guess what? Brown type is not black only so full plate changes all around! 
It boggles my mind that people using InDesign don't know to put all the 4 color in one InDesign file and then put each black version type changes in its own layer in that document. Output a PDF for each version with the base layer and only the black changes layer for that version turned on. Abracadabra....perfection. So easy a monkey could do it.

yeah except even then... we do apparel catalogs that are done that way, should be perfect, but they always find a way to add a challenge. Last year it was to move a 1" version of the logo around a bit, could have been 100% blk logo and would still be ok, but they are experts and the logo was rich black. HA! touché! got us again!

btw, we caught it at press and did some creative hone-offs rather than make all plates but still - grrrr