I think your naps will get a bit better if you increase her A time - am I right in reading she's getting 1:15 first A time - its usually more like 2hr at 4 months (provided she's not a premmie).
You could try leaving the morning feed til 7 and see if she's hungry after 3.5hr. Given you're tanking up, I can't see much value in the DF. You could give it a go but if you're the kind of person who'd have to stay up specifically to do the DF, I'd leave well enough alone wrt night feeds, TBH.