Neutone VST
It has a Demucs quantized model to use in realtime in a DAW
(it uses light “retrained, smaller version” version of Demucs_mmi)
https://neutone.space/models/1a36cd599cd0c44ec7ccb63e77fe8efc/
It doesn't use GPU, and it's configured to be fast with very low parameters, also the model is not the best on its own. It doesn't give decent results, so it's better to stick to other real-time alternatives. It won’t work correctly on low-end CPU (e.g. C2Q), breaking audio in the middle and giving inconsistent audio stream with some random breaks.