Example of passing a system set label to a bevy plugin so the plugin can configure sets as needed, using BoxedSystemSet

main.rs

use bevy::{prelude::*, ecs::schedule::SystemSetConfig};
use bevy::ecs::schedule::BoxedSystemSet;
//// game:

#[derive(SystemSet, Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum MySets {
    GameLogic,
}

#[derive(Resource)]
struct Tick(u32);

fn main() {

    App::new()
    .insert_resource(Tick(0))
    .add_plugins(DefaultPlugins)
    .add_plugins(MyPlugin::new(MySets::GameLogic))
    .add_systems(Update, game_logic.in_set(MySets::GameLogic))
    .run();
}

fn game_logic(mut tick: ResMut<Tick>) {
    tick.0 += 1;
    info!("Incrementing tick to {:?}", tick.0);
}

//// plugin:

#[derive(SystemSet, Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum MyPluginSets {
    PluginLogic,
}

struct MyPlugin {
    after_set: BoxedSystemSet,
}
impl MyPlugin {
    fn new(after_set: impl SystemSet) -> Self {
        Self { after_set: Box::new(after_set) }
    }
}

impl Plugin for MyPlugin {
    fn build(&self, app: &mut App) {
        app.configure_set(
            Update, 
            self.after_set.dyn_clone().before(MyPluginSets::PluginLogic)
        )
        .add_systems(Update, plugin_logic.in_set(MyPluginSets::PluginLogic))
        ;
    }    
}

fn plugin_logic(tick: Res<Tick>) {
    info!("plugin_logic tick = {:?}", tick.0);
}