It is 2019 now. Any permanent way to deal with games ignoring ICC profile ?

Just don't forget to check (visually, by looking at gradient test patterns with your eyes) how much precision you loose (how much [more] "banding" you get on those gradient patterns) by "abusing" the per-channel contrast controls (moving them further than necessary for achieving the desired white point).
Sometimes it's virtually zero, sometimes it looks horrible (it depends on the display).
Also keep in mind (this one you should check with your sensor rather than your eyes) that lower contrast (per-channel or global) results in lower (perceived) contrast ratio, meaning brighter "black" (dark gray) on LCD displays (or darker bright on PDP and OLED). That's why you always want to keep the highest of the three (R,G,B) maxed out (and only alter the other two, for example keep Red maxed out and adjust Green and Blue but the actual combination depends on the display, so start with all three maxed out and work from there by lowering two...).

 

I just install a fresh Win 10 1607 to eliminate fullscreen optimization variable. Still didn't work for those games. Sims 3 for example only use ICC profile on intro video but doesn't respect profile anymore on loading screen.

 

It seems with Win 10 20H1 19041.173 and GeForce driver 450.12 WDDM 2.7, games are not enabled anymore to override ICC profile / Windows night light. At least Heroes of the Storm isn't anymore in fullscreen exclusive (also with FSO disabled), so I'd assume this to be true in general. I really hope it stays that way.
Combined with Guzz' "hack" to enable dithering via registry, this is really great.

Edit: Adjusting gamma curve unfortunately seems to disable dithering.