Coercion, including covert coercion imposed with a soft voice and loving words, is deeply disconnecting, and it certainly does not feel compassionate to the person on the sharp end. What seems to be called ‘Self-led parenting’ is a far cry from the deeply respectful, non-coercive spirit of the Self of IFS when they are talking about adults.
Adding “loving” to “limits” does not make the limits non-coercive, it just adds confusing mixed messages to the coercion. The parents are coercing the child while acting as though that is not what they are doing. They are pretending that they are not responsible for the distress they are in fact causing.
None of the reasons why enforcing “clear borders” is good for coerced children carry over in any way to children who are in consensual relationships with their parents. On the contrary, enforcing fixed borders and bottom lines is irrational and coercive, and sabotages the very means by which such children remain happy.