No. You should not use a password manager for a hardware security device. The point of those (among other things) is to protect you from your computer being compromised. It defeats the point if you stuff the password into your computer. Security is about the weakest link.

Password managers are good advice for 99% of use cases. Protecting an asset worth hundreds of millions is a bit of a special case and you shouldn't follow the same advice as if you were trying to protect your hacker news login credentials.