Thanks for the info, Skinjob!
I did some tests, and probably this would do just for configuring the Transitions tab settings in the screenshot without installing Winamp.
1. Create a sub-folder "Plugins" under your MusicBee\Plugins folder either with normal or portable installation.
2. Save the following text into "milk2.ini" using Notepad and place it under MusicBee\Plugins\Plugins folder you created above.
Whenever the visualization window size in MB changes, the top-half part of this file gets updated automatically. You can adjust the settings in the bottom-half, consulting the screenshot. Those values are Winamp default values. To enable hard cuts, change bHardCutsDisabled value to "0".
Actually I'm now using a full settings file for milkdrop obtained from a foobar version.
But I'm not going to post the content of the file as it won't be useful at all if you don't see the actual settings dialog.
I just followed the instructions here: https://appuals.com/how-to-get-milkdrop-2-visualisations-in-foobar/
And copied milk2.ini file to the aforementioned MusicBee\Plugins\Plugins folder, then it works.
If you want to change some settings, adjust it with foobar using the plugin's settings dialog, and then copy the settings file again.
There are some settings and keys that get overridden by MB, but most work.