NaroCAD is developed in a fast iterative model (3 weeks iteration) including likely two weeks of developing and the third of testing. This makes many things to get better without breaking all things. This iteration seem to be faster than others and it brings many things to the table. As much as the most estimated work that will be done in this time was completed out of schedule.
WPF Options was ported to the smallest details like adding Undo/Redo buttons.
So in this remaining days (will be two days) some small touches may be achieved inside NaroCAD.
One of them is the following: The constrained values in Property Grid will appear with a lock. The nightly build have only line's length checked. But all others will be ported. This change was fairly big in internals as the shape order exposure was not thought in this way. Also, this small redesign permits that one specific shape to have custom property grid items. Supposedly it can be considered that a line will have some extra arguments, that are created with a different property grid items than the default one.
What will mean to you? That it will likely be the most user-friendly release so far. But for now just stay still and try to constraint more shapes in the following release and try to see if you get the lock on the corresponding fields.