I tried v4.0.0 and ran into printing problems on my mac. (See also https://www.mydraw.com/forum/71/Version-300-does-not-print-in-landscape).

I found the download link for the previous version (https://www.mydraw.com/downloads-do-download?downloadid=70126), got the setup pkg and launched it. All seemed normal. Still, v4.0.0 launches.
Then I uninstalled the program (using the usual manner in mac: open the Applications folder in Finder, move the app to the Recycle bin), and installed from the above-mentioned download. Still, v4.0.0 starts up.

How can we downgrade?