See also KeeWeb[0].

Also mutiplatform as KeePassXC, built on Electron. Even though it is built on JavaScript, it has 0 dependencies[1].

And the author responds well on external feedback/contributions[2].

It does support KDBX4[3].

[0]: https://keeweb.info/

[1]: https://github.com/keeweb/keeweb/blob/c651343f80f4f3d41c7d64...

[2]: https://github.com/keeweb/keeweb/issues/104

[3]: https://github.com/keeweb/keeweb/issues/326