Custody of Seed Phrases

Hi IC Community,

Is anyone aware of a service that helps folks self-custody by storing partial seed phrases? There are self-custody services out there like Fireblocks but you need to use their wallet. I am not asking for tools like steel wallets to help individuals but rather asking if there is a third-party custodian out there that can somehow take one section of the seed phrase or shard the whole thing.

Best,
David