Support Residual Classifier-Free Guidance (RCFG) ?

[soryxie]

Is your feature request related to a problem? Please describe. In text2img/img2img pipelines, we use Classifier-free guidance (CFG) to enhance the effect of the condition, which requires 2n computations of model (U-Net): unconditioning term and the original conditioning term.

Describe the solution you'd like. https://arxiv.org/abs/2312.12491 in this work, they introduce RCFG that reduces computations to only n and n+1 times. Will we support this as an alternative featrue? Thanks:)