Thank you. However, I have tried v17.1.3 and there appears to be a slight mishap.
Because if I scroll all the way down, nib moves past its bottom boundary and buries itself into the bottom button of the vertical scrollbar.
The problem can be reproduced by having a document containing a large number of lines relative to the window size. For example, 8000 lines with the window height of 800px.
I think it may be related to the fact that there’s a minimum height of 16px beyond which the nib will not shrink.