I have around 40 yrs. of design, checking, and engineering experience, most of it in aerospace. If this really happened, I don't think this was a standard Boeing practice, nor was this done recently. Boeing is a huge company with many employees. That drawing being drawn, erased and redrawn over and over again sounds like it may have been done 35-40 yrs. ago. This may have happened during the days when drawings were created on the drafting board from ideas or sketches. This was long before Computer Aided Design (CAD) became widely available and today, a standard industry practice. I started on the drafting boards & started using AutoCAD 2D around 1982. Boeing has used powerful CATIA & CADAM, and a few other CAD workstations for Aircraft design work for a very long time before then. Today, Boeing mainly uses CATIA, which is one of the most capable CAD packages available. CATIA allows many engineers, designers, & drafters to work on the same master model, at the same time. I last worked at Boeing Space & Defense from 1996 to 2001, about 24 yrs. ago on the International Space Station. All of our drawings were based on 3D models created on Intergragh EMS CAD workstations. For a long time engineers, designers & drafters have had to check in and check out CAD models and 3D drawings into a data vault. The vault keeps track of it's status, prevents overwritting work, it keeps up with whether it's a work-in-progress or released & under revision control. A decade before, in the mid 1980s, I had worked for Boeing Military Airplane Co.. We had a few ComputerVision CV-4X CAD workstations, but many drawings were still being drawn on drafting boards like they were decades before then. I worked at both Boeing and McDonnell Douglas (now part of Boeing). I was at Boeing when the two companies merged. I did once make a drawing on the drafting board once that was to an ISO standard scale, but not to American National Standards Institute (ANSI) standards and had to redraw it to the correct ANSI scale. It was in ink on mylar, so it required a complete redraw on a large drawing sheet size. This was in 1990, about 35 years ago. I had to explain this to my section chief. This only happened once! He didn't fire me, he said, because he had once did the same thing himself many years before! CAD models are created full size. Drawing are made from these 3D models. Scaling comes in for priming drawings. Now, no drawings should to be scaled (measured).
I also worked for several MROs, companies that completes aircraft maintenance, repairs, and overhauls, and a small aircraft manufacturer. Often they used 2D CAD for creating drawings. Some of them were more freewheeling with drawings. But now they are also using data vaults to track progress, review work-in-progress, maintain revision status/configuration control and for planning.
Future trends point our industry towards model based design and model based engineering (MBD & MBE). Drawings are being eliminated. 3D CAD models will be used to create parts without the need for drawings. This reduces misinterpretation, guess work, mistakes, use of the wrong drawing revision, and the need for as many manual machinist , drafters, & designers. I have seen several drawings at 1/5 scale since, but they had "do not scale" or " not-to-scale" or NTS in the title blocks or someplace in the field of the drawing.