I mean, if Black doesn't play d5 on move 4, you do tend to get an improved king's gambit which is very nice.
And what eval gives you that 4. .. d5 gives all that much?
kaufman gives 1 e4 e5 2 Nc3 Nf6 3 f4 d5 4 fxe5 Nxe4 5 Nf3 Bc5 6 d4 Bb4 7 Bd2 c5 as better for black (then he examines 8 a3, 8 Bd3 and 8 Bb5+ and some earlier white alternatives). i tend to agree but i don't care much either way
openings dont matter too much till let's say 2200 fide so just pick a line you like and play it.
In the long run though, it is better if you just play main lines,because they tend to produce the most rich positions, so you might learn chess faster this way :)