You’ll need to replace the model loader with this fork of the GGUF loader:
https://github.com/molbal/ComfyUI-GGUF
This seems to work best with these modified models:
https://huggingface.co/leejet/ideogram-4-GGUF/blob/main/ideogram4_uncond-Q4_0.gguf
https://huggingface.co/leejet/ideogram-4-GGUF/blob/main/ideogram4-Q4_0.gguf
Big props to molbal, here:
https://www.reddit.com/r/StableDiffusion/comments/1u1i5pd/ideogram_gguf_in_comfyui_works_with_8gb_vram/