Adds `PYTORCH_CUDA_ALLOC_CONF="expandable_segments:True"` to the environment that both DGX Spark nodes share.
In two attempts at this section's manual launch on two GB10 machines (128 GB each), the second with the KV cache fixed as below, each host's available memory fell by 17 to 19 GiB within about 10 seconds after `Loading weights took`, before the server came up. With this setting on both nodes the same start completed and served (MTP 5, answered and called tools). The full report is in [discussion #7](https://huggingface.co/nvidia/GLM-5.3-Flash-FP4-Local/discussions/7).
| Both nodes | Lowest available memory (two hosts) | Result |
|---|---|---|
| Without the setting | 7.8, 7.9 GiB, 5 to 7 s after the weights loaded | stopped by our 8 GiB floor |
| With it | 13.7, 14.5 GiB during the start; 13.9, 15.1 GiB while serving | served |
Both rows used `--gpu-memory-utilization 0.80` (0.87 here), `--max-model-len 131072` (500000) and `--kv-cache-memory-bytes 7650410496`, with the weight…
