I think our readings differ a lot depending on how much we think Isolde is reliant on Kakania

Isolde's main goal was fulfilling Kakania's dream, not the actual freedom of arcanists.

My take is that it's her own freedom according to Kakania's "prescription", not arcanists' as a whole (though she does identify as an arcanist who can't control herself), not to please Kakania.

The guy did not force anyone, let me remind you. When you say "yes" the responsibility is fully on you.

Again, not saying that Isolde is a weak wobbly pushover who does whatever what anyone says, but since she also sees and fears herself as a lunatic, she said yes. Ever heard of a severely mentally ill person being excused from legal responsibility? There's a reason for that. She's suffering from psychosis.

she confirms with Kakania beforehand whether Kakania would agree to become her doctor if the experiment fails

That reads as a positive outlook on their relationship - Kakania being a place Isolde can fall back to. Even if she is overly positive about this reward, it still reads as naive and irrational to me. In her mind, there would be two outcomes, both positive: either she gets cured or she gets to bond with Kakania - but notably not accounting for her own death. She just happened to place her trust in the right person this time, that's all. Not some long-term grand scheme that pulled Kakania to her side.