Of course mileage may vary with different workloads, but are there any good benchmarks/suites to use for comparison in cases like these? They used YCSB but I don't know if those workloads ([1]) are relevant to modern/typical access patterns nor if they're applicable to SQL databases.
You thinking about running some benchmarks in a bcachefs branch (:pray:)?
I want to see this data structure prototyped in PostgreSQL.
Sure, but on principle, looking at the paper, I'd expect it to outperform B-trees since write amplification is reduced, generally. You thinking about cases requiring ordering of writes to a given record (lock contention)?