1. Download the installer from the vendors site.  https://diptrace.com/download/download-diptrace/    My setup is for K-12, so downloaded DipTrace 4.0 Freeware.
   
2. Launch the installer, in this case it was dipfree_en64.exe
3. Once the installer is running, browse to your appdata\local\temp folder, you should see SETUP_($RANDOMCHARS) where $RANDOMCHARS are, well, a few random characters.
4. Copy the contents of that directory to wherever you install from. In my case running SCCM/MEMCM, I created a folder on our primary server with the intention of creating an application using those assets.
5. To install DipTrace silently, call engine.exe /silent
6. The installer takes 1-2 minutes to install. There is an information window that pops up during the "silent" install, but it only shows the files being copied.  I haven't tested this with installing as system yet. Will try to update once I confirm that works too.
   

Comments...

I determined engine.exe was the real installer by watching the dipfree_en64.exe installer with process explorer. dipfree_en64.exe seems to be  the QSetup installer by Pantaray Research. Reading through their documentation, I should have been able to pass /silent to dipfree_en64.ex, but it didn't work.

When running engine.exe through strings, I didn't find any useful data. Was hoping to find other command line arguments, but nope.

Honestly, using /silent was a guess, and it paid off.