What makes a private AI music workflow genuinely useful?

SongForge launches tomorrow. I built it as a native Mac studio for turning a written idea into a playable track, then reshaping it with Rework instead of starting over. After model setup, normal standalone generation runs locally, with no account, credits, or subscription required.

The three decisions I would most value honest feedback on are:

1. Does the first-run model setup explain the download and storage tradeoff clearly enough?

2. Does the Simple / Custom split make sense for both quick sketches and detailed control?

3. When a track is close but not right, does Rework feel faster than regenerating from scratch?

Here is the 23-second product walkthrough: https://youtu.be/5f6WSNjNFYo

What usually breaks your flow in AI music tools?