looking for options to display Photoshop in FULL SCREEN mode in macOS High Sierra, why its not possible, even if I am holding key btn "ALT" on green circle button on top-left corner, there is still just "+" symbol, yes it will make window on full screen but no as a new desktop, for example like safari and other apps.
Photoshop has has a full screen mode built in for years. Merely tap the f key in Photoshop.
Tap F once, fullscreen - with panels/tools
Tap F twice, fullscreen - black background - hide tools and panels
Tap F three times - exit fullscreen.