I love how weird opera gets. Although, I only know it gets weird via hearing about it second-hand from people like yourself. :}

Trust me, we leave out so many of the bonkers parts.

But what does Evie think of Janacek - and I don't just mean Liska Bystrouska, I also mean the delightful insanity that is "The Excursions of Mr. Broucek" (I tried reading the original story for the 2nd Act, where the philistine landlord goes to ~1420 (a time I would dearly like to visit!), via Google Trans. While what I got was rough, it looked like some good fun)
And the only main times the Lead Soprano Rule is different (or she doesn't ALMOST die) in non-comedy opera that I can think of is Der Rosenkavalier.

Oh, she loves Jenufa and Kabanova too, and is intrigued by the idea of Mr. Broucek. She's waiting for a good time to see House of the Dead.

Interesting, all the non-Bel-Canto masters tried at least one non-comic opera where the soprano survives.

Sometimes it's because the piece is a problem play, like "La Rondine" or "Clemenza di Tito."
Or it's like "Siegfried" or "William Tell," where they're trying to be heroically triumphant without being a comedy, but it still ends with a wedding.
Sometimes it's a tricky case, like "Walküre" where she isn't actually dead but she might as well be, or "Turandot," whose title soprano survives because there's another, lighter soprano who dies the most Soprano of possible deaths ("suicide for the sake of an unsympathetically dipshit tenor who immediately throws away the advantage she bought him, and leaves the bass dad to cry and spend the rest of his life alone" ticks off a whole bingo sheet). Sieglinde even gets to die offstage.
And sometimes the composer was trying something radical. That describes all the ones that come to mind, which were considered radical in their time in one way or another - "Don Giovanni," "Cavalleria Rusticana," "Die Frau Ohne Schatten," "Stiffelio," and "La Fanciulla del West" (which manages to have the distinction of being the saddest ending in any opera in which nobody dies. I cry every time).
Or it's something like "Erwartung" or "La Voix Humaine," where it's so experimental there's literally nothing to kill her.

Now I gotta cry over Fanciulla again.