Is there an existing issue for this?

• I have searched the existing issues and checked the recent builds/commits

What would your feature do ?

This feature requires not so much: no a new model class support, only a new sampler

LCM had major update and now we can use it like a regular lora:
https://huggingface.co/latent-consistency/lcm-lora-sdv1-5
https://huggingface.co/latent-consistency/lcm-lora-ssd-1b
https://huggingface.co/latent-consistency/lcm-lora-sdxl

We only need to rename them and put into lora models directory. Set sampling steps to 4, CFG Scale to 1.0. Sampling method to "DPM2" or "Euler a". It gives decent results, but for better work it requires a special sampler, with is similar to others but with little change. You can look how it works in ComfyUI: comfyanonymous/ComfyUI@002aefa

Proposed workflow

1. Go to Sampling method
2. Select LCM sampler

Additional information

How it works now

CompyUI's recent update: