I believe TigerBeetle are alluding to their integration of protocol-aware recovery [1], which is a worthy consideration for the log implementation. Yet another engineering concern which can be offloaded.

If the disaggregated log integrates some mechanism to support leadership "above" it [2], it can be functionally identical to a converged log. Efficiency-wise yes there will be some extra network messages – but networks are very high throughput [3] and fast (sub-millisecond within a cloud region) these days!

[1] https://www.usenix.org/conference/fast18/presentation/alagap... [2] https://maheshba.bitbucket.io/blog/2023/05/06/Leadership.htm..., also on HN yesterday [3] https://blog.enfabrica.net/the-next-step-in-high-performance...