We're actively working on several major improvements including automatic generation of random passphrases and PINs, further improvements to VPN lockdown mode, per-app toggles for access to clipboard content from other apps to go beyond the existing restriction of only the focused app and keyboard being able to read it, etc.
You can look through https://github.com/GrapheneOS/os-issue-tracker/issues with the Feature type and enhancement label. GitHub unfortunately didn't provide a way to automatically migrate the older enhancement label to Feature type. We could use the API for it but haven't yet so you'll need to use both the old and new methods.