`But we don’t just want to keep up; our goal is to push the envelope and explore beyond the boundaries of traditional password management.` Hmmm, sounds like the time to migrate may be sooner than I'd hoped.
You can never trust cloud-hosted password managers..
If you examine the source code of a client (for example bitwarden) and make sure that it's not leaking your master password and then compile the soft yourself and not update - you'll be pretty safe.
This will make it similarly secure as e.g. keepass, because even for keepass you should be sure the source is legit