[4.3.0] Sailfish browser becomes sluggish / unresponsive

I’m wondering if this isn’t related to:

It seems form elements are being repeatedly check with FormAssistant.js when it doesn’t seem they should be. As I understand it, FormAssistant is there to check if the Form Field that is in focus is a password form Username field and should not fire on every character input to ‘any’ form field. But it does.