The inability to paste passwords and secrets is not only frustrating from a user experience perspective but runs counter to recommended security practices. See for example NIST SP 800-63B: "Verifiers SHOULD permit claimants to use “paste” functionality when entering a memorized secret. This facilitates the use of password managers, which are widely used and in many cases increase the likelihood that users will choose stronger memorized secrets."
This limitation makes the import process almost unusable. Not only do many of us use long generated passwords that are not easily entered, but many imports also require application-specific passwords that are long random keys. Typing these is impractical.
Please don't impose arbitrary limitations. And if you are going to hide behind claims of security, have a basis for such assertions.
