When building the model for a triangle building (1 right angle), it is ok for the two main directions, but when trying to build walls, lintels in the last direction, very difficult to have correct connections and a planar structure along this axis. (building bars, dividing, deleting ...)
Could you add an option for snap settings, with a plane (magnetism), defined with vectors allowing easier and quicker model building. All objects created with this option will be in the plane. There are options to change working plane but difficult to use with dwg imports ...