Yeah I'm happy to see this, we have been curious as part of figuring out cloud native storage extensions to GFQL (graph dataframe-native query lang), and my intuition was parquet was pluggable here... And this is the first I'm seeing a cogent writeup.

Likewise, this means, afaict, it's likewise pretty straightforward to do novel indexing schemes within Iceberg as well just by reusing this.

The other aspect I've been curious about is the happy path pluggable types for custom columns. This shows one way, but I'm unclear if same thing.