We would find it very helpful to have ‘Perpendicular’ switch in Polyline command, so when it is enabled, each new segment is constrained to perpendicular direction from the previous one.
Currently SmartTrack can be used but is quite inconvenient and takes a while to ‘get’ that, plus hard to achieve on more complex underlays. Ortho mode also does not help that much if the drawing direction is not aligned with XY, and changing CPlane each time is also more problematic and slows things down. Tracing any technical shapes or building outlines using this mode would be very helpful.
EDIT: the Helpers mode does not help much in Line mode, maybe in Line mode it could actually quickly pick up perpendicular direction instead of adding a brand new switch ?
Hope this small addition can be considered.