Function loader_args 

pub fn loader_args(
    target_dir: &Path,
    profile: &GameProfile,
    ctx: &LaunchContext,
) -> Result<Vec<String>>

The loader’s own arguments for the requested mode, before any caller-supplied extras. An unrecognized loader contributes nothing rather than erroring, so a newer ecosystem schema degrades to a vanilla launch.

For LoaderKind::BepInEx and LoaderKind::Umm, the Doorstop flag spellings chosen depend on more than .doorstop_version: this function also stats target_dir (via is_script_injected) to check whether a loader script is present, because a script-injected launch forces the v4 spellings regardless of the detected version (see doorstop_args’s doc comment). launch_plan_in separately computes the same ScriptInjection fact for resolve_program/LaunchPlan::steam_wrapper, so a single call to launch_plan_in reads that presence off disk twice — same rule, two moments, harmless for a synchronous, non-hot-path computation.