In related news, I've started work on finally using some mission features Ral added a while ago: changing my older hacky "mission has NULL goal and is completed solely via dialogue hacked into" to instead use MGOAL_CONDITION. Though, technically it still has dialogue hacked into it, as that seems to be functionally the only way to add proper "this mission will now success" responses beyond using the fallback "mission complete, I don't know what else to say" option.
However, a big part of that was also making the missions have a better understanding of when the mission can't really be completed, since the success and failure conditions are fairly complex (obtain a specific mutation threshold as the intended endgame, with any competing mutation threshold counting as a failure). So this led to implementing dialogue that makes it possible for a player that'd otherwise be stuck in mission limbo to gracefully fail the mission. This in turn led to setting it so that attempting to start said mission while ALREADY in a state that would fail it will cause the NPC to go "omae wa mou
shindeiru failed" and skip straight to the failure state.
This led to a fairly big feature I'd been putting off for a while: making the NPC better able to nudge the player into pursuing alternative options. This may sound like something simple, but it amounts to basically getting the NPC to correctly grok a checklist of things:
1. Is the item needed to do all this still accessible?
2. Is the current PC a valid candidate, and have they agreed to basically do the unfinished last step all over again?
3. Has the desired mutation fuckery been achieved, despite the mission that revolves around said fuckery being failed?
The end result has basically been adding a complicated backdoor function that gives players a second chance at finishing the mission chain. By this stage it's technically unnecessary, as the purpose of the mission chain is simply a tutorial for accessing and utilizing one of the mod's primary endgame items, but this allows the player to at least bring some resolution to it and not leave the NPC in a state of limbo.
I still need to add one last major dialogue hook (which will also let players who preemptively achieved the end goal to skip being led to do stuff they've already accomplished), then go on to further testing,
but the WIP for it is here.