On a Slot feature, why can't I select Evaluation methods other than Least Square?

[[Gr...]]

On a rounded slot, I need to ensure it'll fit over a pin of a certain size on the narrow dimension. As such, the drawing has an envelope modifier on it meaning I need to select the Evaluation Method of Outer Tangental. Unlike other features, the only evaluation method available is Least Square, which would not give me the correct reading. Am I missing something, or does Calypso only let you do LSQ for special geometry evaluations?

[[Da...]]

I don't know why the slot feature only allows for LSQ. You can check the ends using a circle or cylinder and check the sides as planes and be able to get the inner\outer tangential of each.

[[Ma...]]

If you are talking about classic slot ( like on shaft to transfer torque ), then length is not crucial.
So you can make 2d lines with recalled points ( or plane if you can ).
Or you can use even Symmetry plane

[[Ma...]]

If you have curve you could make it a curve and have more filtering options.