Actually more likely than not, a part of kit engineering was to figure out how to pack the plane in the tightest box possible. This is why one ended up splicing longerons, flat fuselage sides were made out of several pieces with splice braces added as needed, etc. Also, kit engineering included how to get the most pieces packed in a sheet of wood. Less waste reduced wood costs. Plans were printed with sufficient information to build the model, but didn't always show all details in scale. This was to reduce printing costs. Some 50 - 80 years ago, kits were so competitive and they sold by the thousands each year. Being able to eliminate a buck off a kit ensured another sale.

Balsa was cheap enough, that one always had stock on hand, useful for making up parts that were inferior due to wood blemishes. It was just one of the things one learned to do.

Since people overall are no longer into crafts, we don't see the volume and don't see kits in grocery, drug stores, department stores, and etc. Times have changed. What is excellent is cottage support overall.