@WeirdWriter From what I can tell, adaptive mode increases the contrast and font size; markup-wise, it changes the form elements so that the label is attached to the checkbox input through a for= reference, rather than nesting the checkbox inside of the label.

Both approaches should be valid and equivalent to connect the two elements, but I wonder now if some screenreaders handle these cases differently somehow.

(If I can find the time, I'll try setting up a screenreader to see what it makes of it...)