I know Catalina is still in beta so this may improve over time, but I just wanted to report slow 1Password mini performance particularly when 1Password is locked. The mini window will take 4-5 seconds to appear. Once I enter my password, it's generally quicker to pull up when filling websites.
1Password Version: 7.3.2.BETA-0
Extension Version: 18.104.22.168
OS Version: macOS 10.15 19A471t
Sync Type: 1Password