I noticed that too and it does appear to be using spot instances. I have a feeling if it was ran without you may see much better startup times. Spot instances on GCP are hit and miss and you sort of have to build that into your workflow.

In my experience GPU persistent instances often simply don't boot up on GCP due to lack of available GPUs. One reason I didn't choose GCP at my last company.

Oh interesting. Which region and GPU type were you working with? (Asking so I can avoid in future)

I think it was us-east1 or us-east4. Had issues getting TPUs as well in us-central1. I know someone at a larger tech company who was told to only run certain workflows in a specific niche European region as that's the only one that had any A100 GPUs most of the time.