indeed. Neutrino is also a good solution.

I imagine either something like a pruned node or neutrino would be the most likely alternative to a full node. LAN-based syncs would also be possible, but I guess in this specific scenario, it wouldn't solve block storage costs.

Need more details about that "shared blockchain".

On all situations, you will need to trust the source as being the real BTC and not a forked shit. But I supposed this could be verified easily and/or offer a verification tool to users.

bitcoin

Cloud-hosted Bitcoin Node: What is most important to you?

Need more details about that "shared blockchain".
Could be:
- a powerful NAS in the same datacenter that ONLY offers a shared repository for direct access to read the BTC blockchain.
- a BTC node in the same datacenter that provide LAN sync to other nodes in the same datacenter
- a local shared folder from where node operators could copy the data and don't wait for sync

On all situations, you will need to trust the source as being the real BTC and not a forked shit. But I supposed this could be verified easily and/or offer a verification tool to users.