Maybe - it depends on what filters get automagically selected in your modern transceiver. If running AFSK input in LSB mode, your receiver is probably 3kHz wide. In FSK mode you can probably select a narrower receive filter.
It basically depends on what software some YaeComWood video-game programmer wrote once upon a time.
Cheers
Nick K4NYW
Me and a ham club buddy were discussing this yesterday, so I'll throw the question to the wolves; in regards to RTTY, is there any benefit to doing true FSK on a modern radio vs AFSK?
Jeff KC3GJX