After reading a bit more in this thread, I came to the conclusion that one of the issues in terms of narrative (thus, leaving aside all the worldbuilding, map, lore issues) which makes the first steps as a player less of an exploration that emphasizes player agency (meaning [non main plot] decisions and chosen path is contingent and non-linear) and introduces us to the setting, story, and our role in it as a player/character stems from the difference between how in BG1&2 we were effectively left completely free as to either ignore, run away, or pursue our - obviously unavoidable - destiny. No one forces you to actually join up with Jaheira in BG1, you can simply start exploring all the other areas and ignore the main quest/story line for a fairly big part of the game. Same thing is what made BG2 so grandiose, after the linear starting dungeon, you the player are put in a situation which both conveys incentives to follow the main plot (save your hot sis from Irenicus' BDSM nightmare) but also forced you to explore the world (you need to do other quests to get the gold to proceed in the main story/quest). This left a lot of choice in the players hand, you could immediately try to free Imoen, or you could totally ignore her (and your destiny as a Bhaal spawn), at least for a while, and simply set out to become one of the region's great adventurers.
The key point being that the narrative devices employed are much more open ended (e.g. foster father killed in ambush leaving you alone in wilderness with only vague instructions; freeing yourself from imprisonment and finding yourself in a strange city with your sister and close friend taken captive together with the guy who imprisoned and tortured you, with only vague hints as to which path to pursue to find out about your sister and/or who imprisoned you for what reason). The story does not predicate that the player will die because he doesn't want to follow Gorion's instructions or because he doesn't care about Imoen and Irenicus, instead it implies those choices mean you roleplay as someone of questionable morals who pursues his/her own interests instead of doing the obviously good thing (finding out who killed your "father" and saving your sister).
This is very different from BG3 where we are dropped in the world knowing only that we have a life-threatening condition that needs our immediate attention. The lack of narrative choice is so that not even with the current party cast made up solely of evil-neutral companions it makes sense for the player to say 'fuck them tadpoles, I don't care, i'm just gonna do some adventuring instead', as even evil characters do not want to risk losing who they are by turning into a mindflayer. (Except for Astarion that is, the day-roaming vampire thief whose mere existence depends on plot armor). At the same time, however, Larian doesn't want you to rush trough their expensive act 1 map, so quite early they make it evident that there is no urgency at all and the player can freely explore the map and do some quest-lines.
So on the one hand we have a narrative which in roleplaying terms introduces us to the world as an agency possessing character forced to make moral choices right from the start, either willfully or by mere choice of what to do next; while on the other hand, we have a narrative which strips us of all agency (no one, not even the most evil of characters, wants to ignore the tadpole, not even Astarion who merely contemplates the benefits of the tadpole but also by definition can not ignore it) and only manages to introduce player agency and choice by contradicting its own main premise.
I feel that the old story, although a bit cliché and a stereotypical fantasy coming of age trope, was a much better starting premise to give the RP illusion of choice, one can say fuck my sister, I will pursue personal power, but one doesn't say 'fuck that tadpole, I will simply save this guy from the burning inn in what could potentially be my last hours/days and while I feel this thing growing in my skull'. Being on the run, or having to find out something (which is also giving time pressure, IF the player decides to roleplay as someone who cares, but doesn't have to) is much better suited for cascading from side-quest to side quest and getting to know the setting and world, without breaking immersion and contradicting the game's main premises and plot lines, compared to the tadpole which acts a kind of Schrödingers late stage terminal brain tumor.
I think an easy solution would be to only introduce the tadpole at a later stage. This would mean:
- the player starts by noticing something weird, a stain, something out of place and suspects it to be related to the mindplayer abduction
- the quest for a healer to remove the tadpole becomes a quest to find out what this weird stain and change could be
- the player only finds out it is a tadpole at the completion of one of the 'healer' quest lines, meaning that instead of learning we have a 'special' tadpole, we simply find out that we have a tadpole only then. Finding out it is a 'special' tadpole should follow logically from this, either as part of the quests (e.g. the hag could detect the tadpole, hesitate and if player passes insight and charisma check, tell the player she believes the tadpole to be no immediate risk of transforming into mindflayer; or, the player could simply keep resting and using tadpole powers to find out the same thing trough camp/party interactions).
So instead of this giant contradiction as the starting premise of the game and the immersion breaking non-urgent urgency on which it hinges, the player should be left in the unknown about his condition and FIRST find out what is actually happening (e.g. what is this weird feeling, what are these sudden powers I obtained) and only then be told of the exact nature of his/her condition. This would still instill some narrative/moral urgency (no one would NOT want to know what happens to his/her body except the totally suicidal) but not the over the top "we are all going to die, transform in mindless slaves or evil psychic octopus aliens" type of urgency which is so over the top that it forces the main story to contradict itself right from the start.
