Clear type font can be disabled only in 32b. Windows 7.

Now, in actual version no. 44 there isn't this dialog: "opera://flags/#disable-direct-write"

I applied this dialog in windows 7: Control Panel > Performance Options Visual Effects. Uncheck Smooth edges of screen fonts.

Disabling doesn't work in this version: (in windows 7 settings)
Verze: 44.0.2510.1218 (PGO) - Opera je aktuální
Aktualizační kanál: Stable
Systém: Windows 7 64-bit (WoW64)

Disabling successful in this version: (also in windows 7 settings)
Verze: 44.0.2510.1218 (PGO) - Opera je aktuální
Aktualizační kanál: Stable
Systém: Windows 7 32-bit