Two-stage pipeline compatibility after full SFT of LTX2 base model

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Assessment

Difficulty
5/5
Estimated time
Over a week
Newbie friendliness
25/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Stale
Tech stack
python

Research direction

Read the project's two-stage training and inference guidance, focusing on how stage 1 full-model SFT interacts with the stage-2 LoRA trained on the original base model. The issue asks whether that combination is compatible and how to adapt stage 2 after full SFT; done means maintainers clarify the expected workflow or recommend a training strategy.

Written by the indexing model from the issue text.

Description

Hello authors,

First of all, thank you very much for your excellent work and for open-sourcing the project — it is truly impressive!

We have an urgent question regarding the two-stage training / inference pipeline, and we would greatly appreciate your clarification and guidance.

Currently, we are trying to perform full-model SFT on the LTX2 base model (i.e., updating all parameters instead of using LoRA in stage 1). However, we noticed that the generation quality differs significantly between the stage-1 pipeline and the stage-2 pipeline, especially in terms of visual fidelity / image quality.

This raises an important concern:

  • After fully fine-tuning the LTX2 base model, is it expected to directly use the provided stage-2 inference pipeline (which applies a stage-2 LoRA) for generation?

  • Or would the stage-2 LoRA become incompatible with the fully fine-tuned base model, since the LoRA was trained on the original base model distribution?

If incompatibility is expected, could you please recommend a proper training strategy for stage 2? For example: Are there any best practices or training configurations you would suggest for stage-2 adaptation after full SFT?

Thank you again for your time and support. We would be very grateful for any advice or insight!

Dominant language
Python
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