Afaik, none of the modified Netflix apks stream HD videos on non supported devices, they only make a small cosmetic change and show that HD logo. But in reality the quality is still stuck to 540p.
It's the same way cr**k*d Spotify shows extreme audio quality option on settings, but even if you select that option, audio quality is still stuck to 160kpbs.
It only works for devices supporting L1 drm, it forces the app to switch over to play L1 protected content (and that content will only play on L1 certified Devices)
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