Sci-Fi (Adult) - Split setting, present/ near future, and far future. Far future contains training/ growing up in military. Queer themes. Spoilers.

[Jenny]

A novel I read relatively recently, 2019-2021, probably on e-reader, but I can't find it in my Library.

The plot is divided between two time periods, and is divided in alternating chapters of each.
One is present day or near future, but I can't remember much about these parts of the novel. I vaguely remember some thriller-ish plot with several characters, and you aren't told who's good or bad.

The other is far future, and concerns a group of youths who are training to fight a vague enemy, which is somehow linked to the earlier time period - several mentions are made of characters from the first time period. The society in these parts is very scientifically advanced and different from our society, with advanced biotechnology that has affected society a lot - the girl characters are extremely intelligent and characterized as commanders, while the boys are physically adept and have nonhuman companions/minions (may be called "muncs" or some similar reference to haemonculi). This part of the novel has strong Ender's Game vibes of training for a potent/humanity ending threat, but the novel feels much more modern and progressive, with frequent queer relationships, and several adult characters which are biologically and socially beyond the gender binary,

[possible spoilers]
The novel contains wormhole technology, which is described in some detail, and the future setting has many ships which travel at light speed, carrying wormholes that are paired with ones at the human civilization, allowing them to to choose a portal at random to flee through once the great enemy (not a term used in the novel) "catches up" with humanity. This is the conflict for which the teens are training, and which was caused/triggered/occurred in the lifetimes of the characters of the first time period.

I also remember a plot point of the young characters being deliberately put in danger in a plane/shuttle crash orchestrated by the adults to gauge their responses.

[Robert]

Salvation
BTW, it's the first book of a trilogy