Nicely written.

I would add one more thing.

The dryad's love test in Act 3: even if you take the test after freeing Astarion from Cazador, the answers are still the same. His greatest desire is vengeance on Cazador. This breaks immersion a lot for me. Would be nice to see some change in his responses. Ascended version might crave to rule the whole world with his consort, the non-ascended version might be more sincere, just 'want to live'.

But I imagine this is problem for all the companions, although I am not sure, never tried it in the game. For example I doubt there is any difference between Selunite and Sharan version of Shadowheart or with Lae'zel if she is still loyal to Vlakith or not.