Don't think you can make different bleed on front and back in preps
I'd first try and do it in the design app.
Or
Make the page -2mm narrower on the B sides (and zero bleed) but it is a long job to make such a template and you will get errors saying page size missmatch. Centre the pages and +1mm extra bleed to comensate the difference in size
What if you cover with a knockout rectangle of "special colour 3" and then disgard that plate? Or spot colour "knockout white".
I'm wondering, if this is a glue issue in the spine, why you need bleed on the front in the spine?
Like others have already said, Preps 5 allows will allow negative bleed but it will put it on the backing page also, the only way I know of to do it to individual pages is by manually adding a white box on the template. This is how we do it at my work.
Frankly suzyb1078, I don't care for salespeople responding to questions regarding current workflow issues.
Review Suzy's posts - Imposal, Imposal, blah, blah, blah.
Go away please.