[Quest 3|Unity|Anchors] Retrieve spatial anchors from another headset (when oth. heads. is offline)

Hello,

I'm working on a mixed reality project using spatial anchors on Meta Quest 3, with Unity and the Meta SDKs.

Use case:

• A master headset places anchors in a physical environment.

• I want another headset to be able to retrieve those anchors, even if the master headset is turned off.

My questions:

1. Is there any way to manually save/export anchors (e.g. serialize them or store them in a custom/local/cloud service), so I can handle transfer and reuse between headsets myself?
   I haven't found any API to do that yet.

2. Regarding the "Shared spatial anchors" (https://developers.meta.com/horizon/documentation/unity/unity-shared-spatial-anchors/) system with GroupId sharing, I understand that a headset can pull anchors from the cloud even if the original (sharing) device is offline.

   • Can you confirm that this is correct?

   • How long are anchors retained in Meta’s cloud once shared?

   • Are there any conditions (expiration period, retention policy, etc.) that I should be aware of?

I'm addressing this to Meta support and/or developers with experience on spatial anchors with Quest.
Thanks in advance for any help!