Looking at the WorkspaceConfig.xml file before I edit the workspaces and afterwards, then re-examining that file after a software reboot, I've noticed the following.

Editing the workspaces, deleting the default ones so that the only workspaces available are my 4 customs, the WorkspaceConfig.xml file reports NO BuiltIns (default workspaces).

Upon software reboot, the BuiltIns (default workspaces) are back and my customs do not appear in the WorkspaceConfig.xml.

I then moved all the default workspaces to “Do Not Show” and placed my custom workspaces into the bar.

I closed the open project, software went to home screen, I then chose the same project to reopen.

Premiere took 8-9 minutes to reopen that project that I had just closed.

During this time, the WorkspaceConfig.xml file was changed and my custom workspaces remained, and the defaults remained in the Do Not Show.

I closed this project, software went to the home screen, I chose the same project AGAIN to reopen, and it took less than :30 to open, but longer than it should, much longer than it did before we upgraded to CC2019 13.1.2 (build 9).

I can’t reboot the software without having to reconfigure workspaces, then my project load times increase dramatically (4-10 minutes after reconfiguration, before reconfiguration, :30 or less to open)