I am starting to like this program. I found an .ini file tweak "StartPathNewTab=1" which, when XYPlorer is set to replace Explorer as default file manager, will open folders launched by FolderCache via right click, in new tabs instead of overwriting the currently active tab.
Using FolderCache buttons like Side by Side still open Explorer.exe since it is run explicitly. But the ones opened via right click in the FolderCache list or using the Open button should open using whatever is set as the default file manager. XYPlorer loads pretty fast. So even if it is not already open the delay is tolerable.
This way I can still use FolderCache but start to get away from doing everything in Explorer.