from peft import PeftModel
from transformers import AutoModelForCausalLM, AutoTokenizer

base = AutoModelForCausalLM.from_pretrained("google/gemma-4-31B-it")
tok = AutoTokenizer.from_pretrained("google/gemma-4-31B-it")
model = PeftModel.from_pretrained(base, "dementor-research/dpo_chatbot_arena_gemma-4-31b_as_gpt-oss-120b_seed43")

Part of the dementor matrix: 4 source models × 3 cross-targets × 3 train datasets × 3 seeds × 2 stages = 216 adapters.