Random dungeons and BG’s are random for a reason, you can’t simply pick and choose which ones you can queue into otherwise it’s not random. If you want to queue for specific dungeons/BG’s then don’t use RDF
Which is quite honestly a very annoying thing to do, if you don’t want to get queued into Deadmines then use LFD instead of RDF. You shouldn’t make it everyone elses problem that you can’t handle a Deadmines run because you’re tired of getting it and they don’t even take that long to do.
Sounds like you’re wasting your time more by not doing them than actually doing them.