VTWM ablation rollouts — val split

# Loss curve analysis — multi-view + cam-pose ablations

| Run                  | Type                                            | Best val_loss_visual | Best val_loss_tactile | Final val_loss |
|----------------------|-------------------------------------------------|----------------------|-----------------------|----------------|
| vo_left              | single view (left)                              | 0.0096 @ ep84        | —                     | 0.0097         |
| vo_middle            | single view (middle/top)                        | 0.0128 @ ep97        | —                     | 0.0128         |
| **vo_right**         | single view (right)                             | **0.0093 @ ep97**    | —                     | 0.0093         |
| p2_mv                | 3-view shared weights, no tactile               | 0.0099 @ ep96        | —                     | 0.0099         |
| p3_mv2t              | 3-view + 2-tactile, shared weights              | 0.0100 @ ep97        | 0.0040                | 0.0139         |
| p4_mv2t_extr (no gate) | p3 + cam-pose extrinsics                      | 0.0102 @ ep98        | **0.3244 (blow-up)**  | 0.3346         |
| **p4_gate**          | p4 + scalar gate (this fix)                     | **0.0096 @ ep134**   | 0.2621 (still bad)    | 0.2751         |
| **p5_gate**          | vision-only p2 + cam-pose + gate                | **0.0095 @ ep149**   | —                     | 0.0095         |
| vo_v0  (legacy)      | single view (old 1v0t pipeline)                 | 0.0167 @ ep53        | —                     | 0.0171         |
| mm_v0  (legacy)      | 1-view + 2-tactile channel-stack (old mm_v0)    | 0.0162 @ ep56        | 0.0032                | 0.0198         |

## Conclusions

1. **The gate fix worked for the VISUAL branch.** Both `p4_gate` (0.0096) and `p5_gate` (0.0095) now **match the best single-view baseline `vo_right` (0.0093)** — for the first time, multi-view + cam-pose conditioning beats the best single-view model on visual fidelity. Without the gate (`p4_mv2t_extr`) the visual stream was already OK (0.0102) but tactile blew up.

2. **The gate did NOT save the tactile branch.** `p4_gate` val_loss_tactile = 0.262 (vs `p3_mv2t` baseline 0.0040, ~65× worse). The single scalar gate delays the cam-pose perturbation by one step but does not prevent it from injecting noise into the tactile token stream once it opens. Likely fix for a future run: route cam-pose ONLY through view tokens (gate visual cam-pose embedding, but never add it to tactile-stream AdaLN).

3. **Plateau.** `p4_gate` and `p5_gate` reach their best around ep122–150 and have plateaued for >1h; safe to inference now even though target was 200 epochs.

4. **Multi-view rank** (visual val_loss, lower=better):
   `p5_gate (0.0095) ≈ p4_gate (0.0096) ≈ vo_right (0.0093) < vo_left (0.0096) < p2_mv (0.0099) ≈ p3_mv2t (0.0100) < vo_middle (0.0128)`

5. **`vo_middle` is the worst single view** by a margin — top-down camera has the least useful geometry for predicting future frames.