Btw Larian's CEO is responsible for this to some extent , Shadowheart got linked to the main quest on his demand together with her artifcat. The objective was to pass the main story in a natural and seemless way. It ended up mixing a side character with the main plot making her essential to act 1 story line . Her artifact could be an awesome way to make a player-made character unique but it's too late for that i guess. Regardless of what you do Shadowheart will be in your vicinity on some occassions due to this artifact being linked to her story line and the artifcat story line being linked to the main character. And there are consequences to this.
All artifact dialogues seem just "glued" on top of the existing plot in a weird way with shadowheart being like " No no, it makes complete sense, let me explain". Which goes completely against what was suposed to be her " secretive nature" .
It might be interesting to point out that Imoen was originally intended to be an integral part of BG1. And was in BG2 in much the same way as Shadowheart appears to be linked in BG3. So, the interactions that you are calling out here are not without precedent.
As far as the exposition of her character's story arc being a bit contrary to her stated personality, it might simply be a function of trying to get enough information out to the player within the confines of Chapter one, whereas it might/would be more organic to play out over several chapters. Just my thoughts.
