With the author's permission, I have recompiled DaviTools VideoWall for use in Magix versions of Vegas Pro. This is a very useful dockable extension for easily designing and creating video walls that was originally written for use with earlier Sony versions. Here are a couple screen grabs of the UI.
I've added it to the Happy Otter Free Tools library. Here is a direct link where it can be downloaded. https://tools4vegas.com/davitools-videowall-2/
Here is a link to the author's website where detailed help information can be found. http://www.davitools.com/videowall/