I hope the developer reads this and responds. He has been known to read certain posts. I gather, however, that it happens only rarely.
As for users like us, I doubt any of us know the answer. For myself, I also wanted to share my vault library across my Android devices, but I found that not only does the password not take effect in the cloud, but also not on the other device. It seems to be device-specific. The only choice would be to password protect separately on each device, but to sync them, the library is exposed on the cloud, so I gave up.