I finished the update on the female protag path now. From memory, the male protag gets two extra Alexis scenes at the renfair place, two or three Ava scenes, a Mei scene, and a flashback to a Jackie scene. With the female protag, you get some more Alexis nudity, and you get a completely different Kayla path with a few scenes' worth of content, but you miss those others that you get on the male MC path.
Relationships wise, you end day seven in basically the same place with Alexis and with Dakota, on the female MC path you're (much) further ahead with Kayla, and a little further (IMO) with Jackie. On the male MC path, you're (much) further ahead with Ava, plus you have those Mei interactions too.
I have only played as cousin, so I don't know how much difference there is playing as uncle/aunt or family friend. I'm not inclined to find out unless someone advises that it's worthwhile because of a notable difference in content.
Also, I've not used Sancho's mod for this game (I am a fan of his work, so usually I would do) because of his recent absence. From the screenshots of that, it does look like there may be one or two scenes that I've not seen in my playthroughs, plus I found an image in the game folder of an Alexis hj in the toilets of the bowling place, which I've not been able to unlock either. I think the game's gallery is poor, as it's missing a whole bunch of scenes (plus the thumbnails), so I don't know if Sancho is the only available option as a gallery mod? (Note I mean an actual gallery mod, not just a gallery unlocker!)