You can also pick your own epoch and use centiseconds since that epoch for the time component. It's what I do in [1].
[1]: https://docs.racket-lang.org/buid/index.html?q=buid#%28part....
[1]: https://docs.racket-lang.org/buid/index.html?q=buid#%28part....
A.) you pracice having overflows regularly, so the issue is resolved now and not left to some pooor schmuck world war XXVII Survivor in the year 35.000.
B.) It uses every bit, just like a fully random ID, as the key space is filled more densely with each overflow.