I'm not seeing a Java password manager running on iOS. Running Java means having a supported run-time, so both of my principle platforms are a problem.
I wish OpenJDK had a little more development on our platform. The Java approach is better than Qt, as you say, but we have a pretty up-to-date Qt, but not so much with Java.
I'm sorry KeePassXC can not be compiled on our systems. (looking at the build instructions, I don't actually see Ruby, but I also don't know much about porting)
Having a up-to-date build seems critical for KeePass database compatibility.
Another option is Firefox. Our Firefox45 does save passwords, and can be used as a password manager for Dooble or any other new browser that lacks a password manager. It's a very heavy client for just remembering passwords. Synchronizing used to be a problem, and I haven't tried for a while.
Another possibility is Google password. Without Chrome, it is quite limited, but as long as we can access Google from our platform, it looks possible. I may give it a try. If I can access it from Firefox45, that would be a benefit.