I've never played a game with a "speed-up button" (and don't make LPs or watch very many, either), so help me out here. What exactly is it that these buttons are traditionally "speeding up"? The framerate of the entire game (as I believe you could do with the doduo/dodrio modes if playing GB games in Stadium 2)? Skipping or speeding up certain parts of the game, but not others? Are these features intended primarily to make LPers' lives easier, or is this something that a lot of people want in general? Do people really just not want to battle? I'm trying not to be too dismissive about something I don't understand, but if battling in particular is the problem then they're having some kind of issue with the entire point of a Pokémon game. This confuses me and I'd appreciate it if someone could enlighten me as to what, exactly, the complaint is. I'm legitimately curious here.
That said, I do have a few thoughts that aren't just "double/triple the speed of the game overall":
- If the problem is that walking is too slow: As leilou said, running shoes and bikes exist. Give the running shoes automatically at the beginning of the game, and use the HGSS "toggle to have them on/off at all times" option rather than the older "walk by default, hold button to run". (Or, heck, unless you've got some kind of mechanic that involves moving slowly occasionally, like DexNav sneaking or summat, you could very well just ignore the "walking" speed altogether and only include running, because almost no one walks once they have the shoes anyway.) Add a "mach bike" item or gear setting (as in Gen IV).
- If the problem is battle animations: It's been possible to turn those off in canon games since Red and Green back in '96, which means it comes built right in to any ROM hacks. It's an option in Essentials, too, unless it doesn't work and needs to be fixed or something (I've never used it, I don't know). It seems silly to tout this as a "feature", because again, literally in Gen I, but if people somehow aren't aware that this is an option and you feel the need to appeal to the speedster set, then make sure you remind them that it exists. If players want the animations on but would prefer that they be a little snappier, and if you're willing to create/edit said animations, then shorten them by a few frames.
- If the problem is grinding: Do something (idk what, though) to hint to players approximately what level range they should be shooting for next, to set their training expectations appropriately; this way they don't have to wait until they finally hit the gym leader to realize that they haven't trained enough/have spent more time grinding than they needed to. Balance your game so that mindless grinding isn't necessary to reach the appropriate level for the next big event. If there's a chance that a player may need to grind, at least make sure that they have more interesting and somewhat-challenging rematch/training options available to them than "punch a wild pidgey * 10000". Sprinkle a few rare candies around. Add a Gen VI+-style exp. share. Consider increasing experience payout so fewer battles are necessary to reach the levels you want the player to reach, although this requires additional balancing on its own if you're concerned that this might make the game "too easy"; it's not a decision to take lightly, but it's an option.
- If the problem is that players feel they're having too many battles they don't actually need: Reduce the wild encounter rate a little. Make sure it's possible to avoid tall grass and whatnot in most areas. Make sure it's possible to walk around trainers in most areas. Turn off most trainers' ability to confront you when you hit their line of sight and only have battles trigger when they're spoken to directly, so players can pick and choose who and when they fight.
If we're talking about people mashing through your well-written dialogue and so on (which sounds like a different concern from cutting down LP time—if someone's showing off your game, wouldn't they want to show off the story?—but again, I dunno *shrug*), you have to consider whether they even care about those things in the first place. Yes, as a developer you pour a lot of love into your projects. Yes, there are players who appreciate all the hard work and little details. But if a player actively wants to fly through the dialogue in your game as fast as possible, well, I'm sorry but it sounds like they just don't care that much about your story, no matter how good it is. And if they've decided they're not interested, all that means is that they'll button-mash through the text at whatever speed is available; they still won't pay attention if there's no speed-up, they'll just not pay attention but it'll take longer. You don't need to pander to those players, though. They can go find a game that's lighter on story (or whatever) and enjoy that instead.
Are players complaining that your game is slow because there are things you could be doing as a designer or developer to improve overall enjoyability for everyone? Because they'd like a few extra options to reduce delays and repetition in their videos? Or because they want to play the game as Usain Goddamn Bolt? Personally I enjoy battling as long as no unreasonable grinding is required, and if I were to LP a game I'd have no problem playing normally and then cutting the training montage out of the video before posting it (not an option for livestreamers, I suppose, but eh), but if there are other issues then I guess it wouldn't hurt to look at them? I dunno? Concessions for LPers are a nice thing to have, I suppose, but presumably you're not making your game for the express purpose of having it LPed, any more than the canon games are. A game is first and foremost meant to be enjoyed by whoever's actually playing it, not people who might hypothetically be watching that person's screen, and if folks have expectations going above and beyond that, well, they're missing the point a little bit, aren't they?
And if the problem is the first one—your game is just too grindy or what have you—then a turbo button is a cop-out that lets you avoid fixing your shoddy design decisions. So... make better design decisions.
(one of these days I will learn to write short posts, ugh)