Press "End+F9" to show stripes in lagless vsync mode. Open setting window then continue emulation. Stripes are no longer visible so you have to press End+F9 again to show them.
Load the config below. In display settings, full-screen resolution is set to Native (3840×2160 in my case). Start emulation. The Amiga display is scaled far too large. Open settings window, change resolution to 3840×2160 and continue emulation, then display appears as it should.
Code:
http://www.media!fire.com/file/ynv4onil9ig64iq/A500_1.2_test_DX11_DOC_15.uae.7z