Though the slowdown on long pages is definitely a thing, and definitely annoying, even on PC. IMO, though, that's something to complain about to Fandom. If we want to use our personal encyclopedia to list things, and we have many things to list, they ought to support that, and frankly, I don't know why the problem exists. Even our largest pages shouldn't take that much computing power to handle.
Anyway, the more people who complain about a thing, the more likely it is to get attention. Even better if it comes from mobile users, since they really have a hard-on for the mobile experience.
In the meantime, if we do start breaking out sections of the Killed Badfic list by continuum, I'd say let's just take it to its logical conclusion: Missions are already listed on continuum pages, so rather than have redundant continuum pages to list killed fics, just add the fic info to the existing pages, as a sub-bullet to the corresponding mission (sans editorial commentary; that's what the mission is for). Then we could even do away with the Killed Badfic lists entirely, which would be fine by me.
... We could trim down the lists by simply removing the bullets of editorial commentary, come to think of it. Some of them are ridiculously long.
~Neshomeh