Manual collection of pipe lengths

On most civil plans, the lengths of pipe segments are provided by the engineer. I also use a program called On Screen Takeoff. In it, when you create a condition (zz calls them takeoffs) such as a linear segment, you can set the condition to “manual”. When you draw the segment, a box opens on the segment and allows you to input the engineer’s value. This value overrides what would be collected by the scaled segment length. It allows you to do this for every segment you draw with that condition. In this way, you can easily collect and total the lengths proposed by the engineer. zz does have a manual segment type but it doesn’t seem to fit this use case. I've included some pictures as examples.