108881 added synthetic source support for `geo_shape` by cloning raw field data and storing it. There is a possible optimization here - synthetic source can be constructed from a stored field that uses binary WKB format (already existing and enabled via `store` parameter).

In order to implement this we need:

Set store to true by default when using index mode with synthetic source.
Implement SyntheticFieldLoader that retrieves data from stored field.
Add ignore_malformed support. Current implementation covers ignore_malformed by default but with this change we'll need a special implementation.

Note that shape is stored after normalization indexer.normalize(geometry) which means that it can be different from source shape data.

elastic / elasticsearch