Todd Blankenshipさんのイラストまとめ

Besides streamlining the timeline back-and-forth, the other notable manga difference for this section is that Black starts off using an ordinary (gold-haired) Super Saiyan form, before his fight with Vegeta pushes him to acquire Rosé.

Meanwhile, in yet another timeline, the Future Trunks and Mai we know and love (?) show up, meet their doubles, beat Babidi without Shin dying, and have Beerus and Whis take care of Zamasu and Black for them, thus leaving them free to live a peaceful yet awkward life from then on

This is essentially the explanation given in the DBS manga: Trunks says the time machine is still left as-is from when it was last used, since changing the setup will probably leave him unable to go to the same world (timeline).

Why 17 years, anyway? In the android/Cell arc, Trunks first travels 20 years into the past to warn Goku, then shows up to help them fight the androids three years later. 20-3=17, so presumably the assumption was that this time gap remains fixed.

Toyotaro remains cagey about the exact year of the Future Trunks stuff in the DBS manga, with a teasing panel showing a newspaper too ripped up to read the date. Still, the “17 years into the past” part remains, so even disregarding Xenoverse, the date can’t be much past 797.

While Bulma slowly gathers enough blue time travel goo, Trunks battles Goku Black for an entire year. So, sticking with 796 as the date of the final battle, Black should arrive on Earth in 795. Precisely how long it’s been since Black and Zamasu first hooked up is unknown, though

Tomorrow: resistance is futile!

So that’s sometime between 788 at the earliest and 795 at the latest for Future Trunks’ own personal Buu arc. Regardless, that’s way later than the main timeline, where Babidi made his move in 774. In the DBS manga, he notes how it took him over ten years to gather enough energy.

In the DBS manga, Trunks describes his battle with Babidi and Dabura as “a few years” ago (from his perspective), but also says Black appeared “soon afterward”…

All versions of this scenario are obviously set after Future Trunks defeats imperfect Cell in his own timeline (in 788). The Super version(s) occurs sometime before Goku Black arrives on Earth (a year before Future Bulma’s death in 796, when Trunks returns to the past)