When using the fountain pen with Apple Pencil rotation enabled, users must constantly re-adjust their grip to keep the nib horizontal. Locking rotation forces a fixed default angle that often looks unnatural for a fountain pen.

Please add the option to lock the nib at a user-defined angle, for example by letting the user set the angle with a slider so the pen hits the page the same way every time. See image for example. This would greatly improve writing flow, style and comfort.