Why does the Software Updater window resize between download and install?

This has driven me crazy for years.

The software update process starts and I resize the window width and height as it is downloading the updates.

At the fifty percent point, the software update process changes to the installation mode, and the window resizes back to the default, small size again, causing the text to wrap instead of being able to see the long lines.

I then have to resize the window again.

Argh! Why doesn't it keep the window size that I resized it to during the download process?