chroma: further decreased learnign rate

configs/CHROMA.knf.yaml

@@ -229,7 +229,7 @@ training:
     subset_warmup:
       enabled: true
       subsets: [genitals, fullbody, head]
-      steps: 600   # !! First steps of the total run are ONLY listed subsets!
+      steps: 1000   # !! First steps of the total run are ONLY listed subsets!
 
     # Full-run trainer config. trainer_testrun below overrides selected keys
     # only when knf lora sync/train is called with --testrun.
@@ -239,9 +239,9 @@ training:
       hub_model_id: ladybird-chroma-lora            # Optional Hub model id if push_to_hub is enabled.
 
       optimizer: adamw_bf16        # BF16 AdamW optimizer.
-      learning_rate: 0.00007        # Conservative Chroma LoRA starting point.
+      learning_rate: 0.00005        # Conservative Chroma LoRA starting point.
       lr_scheduler: constant_with_warmup # ramp up LR to avoid weird color biases.
-      lr_warmup_steps: 100
+      lr_warmup_steps: 200
       seed: 42                     # Training seed.
       gradient_checkpointing: true # Reduce VRAM by recomputing activations.
       max_grad_norm: 1.0           # Clip gradients for stability.
@@ -250,7 +250,7 @@ training:
       train_batch_size: 4            # Per-device batch size.
       gradient_accumulation_steps: 1 # Effective batch multiplier.
       num_train_epochs: 0            # Step-based training; max_train_steps controls run length.
-      max_train_steps: 1800          # ANIMA-aligned Chroma character run with extended warmup.
+      max_train_steps: 4000          # ANIMA-aligned Chroma character run with extended warmup.
       ignore_final_epochs: true      # This fixes early stop due to weird epoch calculation by simpletuner
 
       caption_dropout_probability: 0.0  # Disable caption dropout; keep trigger behavior stable.
@@ -259,8 +259,8 @@ training:
       # push_to_hub: false          # Upload final artifacts to Hugging Face Hub.
       # push_checkpoints_to_hub: false # Upload intermediate checkpoints.
       checkpoints_total_limit: 5       # Keep latest 5 checkpoints.
-      checkpoint_step_interval: 200    # Save checkpoint every 200 steps.
-      validation_step_interval: 200    # Run validation every 200 steps.
+      checkpoint_step_interval: 400    # Save checkpoint every 200 steps.
+      validation_step_interval: 400    # Run validation every 200 steps.
       validation_on_startup: true      # Render baseline validation before training.
       validation_prompt_library: false # Disable SimpleTuner built-in prompt library.
       validation_disable_unconditional: true # Skip unconditional validation branch.