I see a fairly noticeable delay in drawing of the ST3's window after I click its button on the taskbar - for around half a second there's a white rectangle in place of the actual UI.
This is more noticeable on my main box (4k, 200% scale) then on my other one (1920x1200, 125% scale).
All visual effects are disabled.
Windows 10 64bit
ST 3.1.1 (3176) 64bit