[barkingcat]

why does this need a technical solution? Just type in the password. Presumably if the system is important enough to be airgapped and needs a 100+ character randomized password (without copy paste and without hardware keys), it is important enough for you to spend the time to memorize and type in the passwords.

Otherwise, it is just security theatre if you won't even spend the time to make absolutely sure that 1) you are typing into an authorized device that won't log your key strokes, and 2) that using any other "assistance" mechanisms represents a breach in the security of this system.

Just friggin memorize it and type it in. For me, I memorize my bank password and PIN even though it's very complicated. This information is important enough for me to commit the time and not cheapen out by "relying on a tool". Of course, I keep it in my password manager as a record, but in daily use I absolutely do not say to the teller: oh I need to look it up. I recite to the bank my passphrase and other id confirmation by memorization, I know it even better than my own phone number.

If you need multiple people to log in, each person should have a different password, only memorized by that person alone.

If the person can't memorize it, I would say either change the design of the system or fire this person because "they had one job: to memorize and type in this password".