A receive EQ in CW mode won’t do very much for you. CW is a very narrow tone, nearly a single frequency. An EQ is a series of frequency adjustments across a wide band of frequencies. The only use for CW mode that I can tell may be to adjust for the sound quality of the overall band hiss if you are listening in wide mode hunting for a signal.
Once you have zeroed a signal to work, if you just drag your filters in, all the surrounding hiss and noise will go away, leaving you with the single tone that you are listening to.
If your preferred offset is say 630 Hz, you could conceivably set your offset to one of the matching fixed EQ frequencies and use it as a peaking filter in some regards by boosting it so it would emphasize an incoming signal as you zero it. That’s about the only thing I can think of to apply the RX EQ for CW use.
If for some reason you haven’t realized the filtering can be dragged to custom widths yet, it’s simply stunning.