Thanks for trying . . . BUT . . .
Re: AND, you must have disabled the “Close Windows when quitting apps†feature in Mac OS system settingsI used to have this disabled. However, the next time the app is launched - in my case, PREVIEW - it automatically opens the last document which was used in that app AS WELL AS the new one selected to open. Most annoying. The only way to avoid that, as far as I know, is to select "Close Windows When Quitting Apps" so that only the desired file opens the next time the app is launched.
Oh, well, one can't have everything, I suppose.