There are two ways to bounce mono files in Logic Pro X.
Bouncing From a Mono Output
Logic Pro X bounces audio straight from an output. If your output is stereo, initiating a bounce will produce a stereo audio file. A mono output will produce a mono audio file. So, simply make your output mono if you want a mono bounce.
The two files that are important to us are Concert.patch and workspace.layout. As I mentioned earlier, Concert.patch contains all your patches and sets. Workspace.layout is your concert’s layout template.