Changing a vector point’s handle while you’re editing is different from Illustrator. It would certainly be a little bit more efficient to have that option-key shortcut, but instead here is Sketch’s fastest way to create a vector point with “Disconnected” handles:
- Click to add the new vector point (drag if you want to do some preliminary positioning on the handles).
- While that most recent point is still selected, click the “Disconnected” icon in the Inspector. OR, as a shortcut, press the “3” key to switch to “Disconnected” mode. The keys 1, 2, 3, and 4 correspond to those 4 vector handle modes, and can really speed up your workflow.