Recent files list not clearing

After uninstalling Photoshop CC 2018 and installing Photoshop CC 2019 all the recent files reappeared in the welcome screen.

Even when I cleaned the list again, uninstalled Photoshop CC 2019 and reverted back to CC 2018, the file list was there along with the thumbnails.

I tested another scenario. I set recent file list to zero and opened a bunch of files. When I reset the number of recent files to 20, everything I had earlier edited appeared.

All recent files are stored in C:\Users\<user>\AppData\Roaming\Adobe\Adobe Photoshop CC 2018\Adobe Photoshop CC 2018 Settings\MachinePrefs.psp (use a hex editor to open it).

Is there a way to hard-delete recent file list from Photoshop other than deleting MachinePrefs.psp?

I consider this a major breach to privacy since we use a no cache policy to avoid shadow IT.