One of the numerous pleasant aspects in Rhino are the ingenious modeling aids. These two would would be a welcome complement to the existing toolset:
Custom SmartTrack lines:
When adding 2 consecutive smart points, there’s currently only an undocumented Mid-snap, when hovering near the midpoint between the points. This should be extended to a full-fledged smart line.
Aligned angle constraints:
Currently, when the direction to the last picked point is angle-constrained (by entering <angle in the command line), the 0°-constraint direction always points to the X-axis of the construction plane. But what, if one needs to pick a point, which is angled to a direction that deviates from the constraint subdivisions? As far as I can see, the geometric location must then first be explicitely constructed, e.g. via _Line _Angled.
A better solution would be to combine Direction Lock (pressing TAB once) with Angle Constraint: When the direction is locked and an angle constraint is entered, the locked direction defines the 0° angle constraint. At the moment, angle constraints during direction lock are just ignored.