I've only changed I/O in DVDDecrypter a few times to test DVDD with
DVD43. With earlier versions of DVD43, you needed Patin-Couffin access layer. So that's how I set I/O in DVDDecrypter, and it worked. The newest version is a standalone program, so I uninstalled Patin-Couffin, I/O in DVDDecrypter set to SPTI-Microsoft. That works too. For all I know, it would work without changing I/O.
Don't have any ELBY software, dunno. Nobody's posted yet to say I'm wrong. (AnyDVD with I/O in DVDDecrypter set to ELBY).

So why not give it a try?
BTW, most times it's kinda redundant to use DVD43 and DVDDecrypter together. I use it mainly with VobBlanker. DVD43 seems to be one of those programs people either love or hate, depending on whether it works for them.

It works for me, and is occasionally useful.