meters that are relevant to training SDXL in this guide. --pretrained_vae_model_name_or_path: path to a pretrained VAE; the SDXL VAE is known to suffer from numerical instability, so this parameter allows you to specify a better VAE --proportion_empty_prompts: the proportion of image prompts to replace with empty strings --timestep_bias_strategy: where (earlier vs. later) in the timestep to apply a bias, which can encourage the model to either 