Decaying threshold reduces the risk.

If you’ve got that setup it’s not as bad but you’re still locked out of your own funds for some period if you lose a key. That inherits the risk profile of time locks where if you feel like your keys are compromised or at imminent risk then you can’t move funds to a new setup in time. It really depends on your threat model.

If you’re backing up 3 sets of keys then you’ve got at least 6 to keep up with, which makes recovery easier, but for each one you have to maintain security. It creates more opportunities to leak your keys.