Works really well, personally only tested on Linux, but I love it!
It’s the clipboard, you shouldn’t put secure items on the clipboard generally speaking. (We all do it anyway)
Password managers are the bees knees if you have to use a password, I do like the authenticator only logins especially if you have an obnoxious number of sites you have to login to. I will say though, that clipboards are tricky especially in an environment where VNC/Screen Connect etc are actively used. Screen Connect especially will happily grab the clipboard contents and share it with the other user.