A seed that was once a HOT wallet (MetaMask) is never considered safe, and should only be used with assets that can NOT be moved to a safe wallet. This would be items like nodes or tokens/NFTs locked in staking. You can put that seed on a hardware device to better protect the assets, but since it isn’t truly safe I then highly recommend a second hardware device with a different safe seed that is a COLD seed (created in the device). Use this second device for all new assets; nodes, NFTs, tokens and any assets you can transfer out of the HOT seed to it. If you need to restore a seed (due to lost/broken hardware device) I would only put the seed words into another hardware device, except in an emergency.