Aff. Designer 1.6.4.104
According to the manual I should be able to select a node (via the Node tool) on an already drawn curve and Shift+drag the handle to constrain it to a 45deg intervals. It doesn't work. Shift+drag just slides the handle along the imaginary line defined by the original orientation of the handle.
From the manual Drawing curves and shapes > Edit curves and shapes:
Is this supposed to work at all? Maybe I just misunderstood the info in the manual. Or is it indeed worded incorrectly? Maybe it should read "The Shift key constrains the node to 45 degree intervals". Then it would make sense.