Let me clarify the context of our discussion...
We are mainly talking about (or at least that's what I though initially) the newly introduced (or rumored) FBI/CIA checks that caused I-485 freeze - and NOT the usual INS procedure so far that anyway checked background by ways of FP (through FBI) and databases for G-325A verifications, etc. The background checks are not questioned per se - the concern was about renewed/newer checks and subsequent delays.
Also, in CP they take finger prints at the time of consular interview (for security check) and in the afternoon, they give you visa papers - that means consulates have some alternate ways of checking FP so fast (they won't give you visa unless FPs are checked, right?)! They also take another FP at the port of entry for greencard.
Best wishes,
Jigesh