Note that version 3.2.x will mess with your preferences if it is opened after an earlier version (for example, 3.1.1) has been opened. There are apparently enough differences between the preferences that the developers felt it was safer for 3.2.x to return to some defaults. 3.2.x will also re-enable all the default effects.
There is a way for each version of Audacity to have its own preferences, but I’ve never tried it.
each version of Audacity to have its own preferences
Portable? I’ve never tried it, either. The down side if you have to install all your custom settings and extensions for each one. If you do things the way I do, you leave one out. “Son of a sea cook! Where did I put the framistat filter?”