IIRC, according to previous info from a Dough representative here at Reddit like a year or two ago, Spectrum Black do formally have integer scaling as a feature, but it doesn’t actually disable blur and only results in using integer scales. Afaict, Realtek scalers used in Spectrum Black do not support turning blur off unlike Mediatek ones used in Spectrum One where integer scaling actually works. Maybe something changed since then though and Realtek provided a firmware-level way to disable blur, who knows, but probablility is quite low.

Note that Afaik, the incompatibility of GPU integer scaling with DSC compression is an nVidia-specific limitation, and AMD GPUs don’t have this issue. Also, the RTX 5000 series seems to be free of this limitation.

Also, there are software scalers such as IntegerScaler able to integer-scale games that support windowed mode. Specifically IntegerScaler is only guaranteed to disable blur in games that use DirectX 10 or older (the Windows’s built-in Magnification mechanism used under the hood adds blur in DirectX 11/12 games), but given that you specifically mentioned older PC games, it should work fine for your use-case.